Add announcer script

I always keep writing up this same announcement message whenever I publish a new version.

I've now written a script to automate my announcement formatting, it looks like this:

```
**MetaMask 2.13.2** now published to the Chrome Store! It should be available over the next hour!
 2016-10-4

- Fix bug where chosen FIAT exchange rate does no persist when switching networks
- Fix additional parameters that made MetaMask sometimes receive errors from Parity.
- Fix bug where invalid transactions would still open the MetaMask popup.
```

1 files changed, 2 insertions, 1 deletions

diff --git a/package.json b/package.json
index b59a7ca44..72c682173 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,8 @@
     "mock": "beefy mock-dev.js:bundle.js --live --open --index=./development/index.html --cwd ./",
     "buildMock": "browserify ./mock-dev.js -o ./development/bundle.js",
     "testem": "npm run buildMock && testem",
-    "ci": "npm run buildMock && testem ci -P 2"
+    "ci": "npm run buildMock && testem ci -P 2",
+    "announce": "node development/announcer.js"
   },
   "browserify": {
     "transform": [