Fix lint warnings

Fixed warnings:
```md
app/scripts/controllers/computed-balances.js
+ 35:27  warning  Missing space before function parentheses            space-before-function-paren
+ 41:14  warning  'address' is never reassigned. Use 'const' instead   prefer-const
+ 61:9   warning  'updater' is never reassigned. Use 'const' instead   prefer-const
+ 68:11  warning  'newState' is never reassigned. Use 'const' instead  prefer-const

app/scripts/controllers/network.js
+ 104:29  warning  Missing space before function parentheses  space-before-function-paren

app/scripts/lib/createLoggerMiddleware.js
+ 4:32  warning  Missing space before function parentheses      space-before-function-paren
+ 15:2   warning  Newline required at end of file but not found  eol-last

app/scripts/lib/createOriginMiddleware.js
+ 4:32  warning  Missing space before function parentheses      space-before-function-paren
+ 9:2   warning  Newline required at end of file but not found  eol-last

app/scripts/lib/createProviderMiddleware.js
+ 5:34  warning  Missing space before function parentheses      space-before-function-paren
+ 13:2   warning  Newline required at end of file but not found  eol-last

app/scripts/lib/events-proxy.js
+ 1:50  warning  Missing space before function parentheses      space-before-function-paren
+ 31:2   warning  Newline required at end of file but not found  eol-last

app/scripts/lib/nodeify.js
+ 2:22  warning  Missing space before function parentheses  space-before-function-paren
+ 2:24  warning  Missing space before opening brace         space-before-blocks
+ 5:18  warning  Missing space before function parentheses  space-before-function-paren
+ 5:20  warning  Missing space before opening brace         space-before-blocks

app/scripts/lib/pending-balance-calculator.js
+ 16:19  warning  Missing space before function parentheses  space-before-function-paren

app/scripts/lib/pending-tx-tracker.js
+ 85:11  warning  '||' should be placed at the end of the line  operator-linebreak
+ 87:11  warning  '||' should be placed at the end of the line  operator-linebreak
+ 88:11  warning  '||' should be placed at the end of the line  operator-linebreak
+ 90:11  warning  '||' should be placed at the end of the line  operator-linebreak
+ 91:11  warning  '||' should be placed at the end of the line  operator-linebreak

app/scripts/lib/port-stream.js
+ 3:22  warning  Missing space before function parentheses  space-before-function-paren
+ 3:24  warning  Missing space before opening brace         space-before-blocks

app/scripts/lib/tx-gas-utils.js
+ 84:2  warning  Newline required at end of file but not found  eol-last

app/scripts/lib/tx-state-history-helper.js
+ 12:37  warning  Missing space before function parentheses      space-before-function-paren
+ 23:30  warning  Missing space before function parentheses      space-before-function-paren
+ 30:23  warning  Missing space before function parentheses      space-before-function-paren
+ 35:28  warning  Missing space before function parentheses      space-before-function-paren
+ 41:2   warning  Newline required at end of file but not found  eol-last

app/scripts/lib/tx-state-manager.js
+ 94:13  warning  'value' is never reassigned. Use 'const' instead  prefer-const

ui/app/reducers.js
+ 45:7  warning  'state' is never reassigned. Use 'const' instead        prefer-const
+ 53:7  warning  'stateString' is never reassigned. Use 'const' instead  prefer-const

ui/lib/tx-helper.js
+ 27:2  warning  Newline required at end of file but not found  eol-last

ui/app/components/account-dropdowns.js
+ 163:1  warning  More than 2 blank lines not allowed  no-multiple-empty-lines

ui/app/components/menu-droppo.js
+ 22:7  warning  'style' is never reassigned. Use 'const' instead  prefer-const

ui/app/components/shapeshift-form.js
+ 135:11  warning  '&&' should be placed at the end of the line  operator-linebreak

ui/app/components/typed-message-renderer.js
+ 35:25  warning  Missing space before function parentheses      space-before-function-paren
+ 42:2   warning  Newline required at end of file but not found  eol-last

mascara/server/index.js
+ 11:42  warning  Use path.join() or path.resolve() instead of + to create paths  no-path-concat
+ 12:36  warning  Use path.join() or path.resolve() instead of + to create paths  no-path-concat
+ 13:33  warning  Use path.join() or path.resolve() instead of + to create paths  no-path-concat
+ 14:40  warning  Use path.join() or path.resolve() instead of + to create paths  no-path-concat
+ 20:29  warning  Use path.join() or path.resolve() instead of + to create paths  no-path-concat
+ 21:29  warning  Use path.join() or path.resolve() instead of + to create paths  no-path-concat
+ 26:40  warning  Use path.join() or path.resolve() instead of + to create paths  no-path-concat
```

1 files changed, 8 insertions, 7 deletions

diff --git a/mascara/server/index.js b/mascara/server/index.js
index 24739b43f..f0d022f7d 100644
--- a/mascara/server/index.js
+++ b/mascara/server/index.js
@@ -1,3 +1,4 @@
+const path = require('path')
 const express = require('express')
 const createBundle = require('./util').createBundle
 const serveBundle = require('./util').serveBundle
@@ -8,22 +9,22 @@ module.exports = createMetamascaraServer
 function createMetamascaraServer () {
 
   // start bundlers
-  const metamascaraBundle = createBundle(__dirname + '/../src/mascara.js')
-  const proxyBundle = createBundle(__dirname + '/../src/proxy.js')
-  const uiBundle = createBundle(__dirname + '/../src/ui.js')
-  const backgroundBuild = createBundle(__dirname + '/../src/background.js')
+  const metamascaraBundle = createBundle(path.join(__dirname, '/../src/mascara.js'))
+  const proxyBundle = createBundle(path.join(__dirname, '/../src/proxy.js'))
+  const uiBundle = createBundle(path.join(__dirname, '/../src/ui.js'))
+  const backgroundBuild = createBundle(path.join(__dirname, '/../src/background.js'))
 
   // serve bundles
   const server = express()
   // ui window
   serveBundle(server, '/ui.js', uiBundle)
-  server.use(express.static(__dirname + '/../ui/', { setHeaders: (res) => res.set('X-Frame-Options', 'DENY') }))
-  server.use(express.static(__dirname + '/../../dist/chrome'))
+  server.use(express.static(path.join(__dirname, '/../ui/', { setHeaders: (res) => res.set('X-Frame-Options', 'DENY') })))
+  server.use(express.static(path.join(__dirname, '/../../dist/chrome')))
   // metamascara
   serveBundle(server, '/metamascara.js', metamascaraBundle)
   // proxy
   serveBundle(server, '/proxy/proxy.js', proxyBundle)
-  server.use('/proxy/', express.static(__dirname + '/../proxy'))
+  server.use('/proxy/', express.static(path.join(__dirname, '/../proxy')))
   // background
   serveBundle(server, '/background.js', backgroundBuild)