[npm] Update to stacktrace-parser@0.1.3 and ws@0.8.0 to satisfy io.js 3 / Node 4

The previous version of stacktrace-parser 0.1.2 had an line in its package.json file that required Node <= 2.x. That line was removed, so it no longer warns on io.js 3.x or Node 4.x.

Similarly, ws 0.8.0 was published with support for the new V8, so it compiles with io.js 3.x and therefore should work with Node 4.x.

Updated the Travis file as well to run on io.js 3.x.

Test Plan:
```
$ nvm use iojs-v3
Now using io.js v3.1.0 (npm v2.13.3)

$ npm i
<no compiler errors>
```

.travis.yml

@@ -8,16 +8,16 @@ cache:
         - .nvm
 
 before_install:
-  - brew update
+  # Update brew twice because the first run can fail: https://github.com/Homebrew/homebrew/issues/42553
+  - brew update; brew update
 install:
   - brew reinstall xctool nvm
-  - rm -Rf `node -p "require('os').tmpDir()"`/jest_preprocess_cache
-  - npm install -g flow-bin@`node -p "require('fs').readFileSync('.flowconfig', 'utf8').split('[version]')[1].trim()"`
   - mkdir -p .nvm
   - export NVM_DIR="$PWD/.nvm"
   - source $(brew --prefix nvm)/nvm.sh
-  - nvm install iojs-v2
-  - nvm use iojs-v2
+  - nvm install iojs-v3
+  - rm -Rf `node -p "require('os').tmpDir()"`/jest_preprocess_cache
+  - npm install -g flow-bin@`node -p "require('fs').readFileSync('.flowconfig', 'utf8').split('[version]')[1].trim()"`
   - npm config set spin=false
   - npm install
 

package.json

@@ -69,12 +69,12 @@
     "sane": "^1.1.2",
     "semver": "^4.3.6",
     "source-map": "0.1.31",
-    "stacktrace-parser": "frantic/stacktrace-parser#493c5e5638",
+    "stacktrace-parser": "0.1.3",
     "uglify-js": "2.4.16",
     "underscore": "1.7.0",
     "wordwrap": "^1.0.0",
     "worker-farm": "^1.3.1",
-    "ws": "^0.7.2",
+    "ws": "0.8.0",
     "yargs": "1.3.2",
     "yeoman-environment": "^1.2.7",
     "yeoman-generator": "^0.20.2"