Add option logSnippet

I'm having trouble making the test work, if you have any idea ?

 1) E2E `logSnippet` option Can set the log snippet when given in options:
     TypeError: Cannot read property 'args' of null
      at Context.<anonymous> (C:\wamp\www\browser-sync\test\specs\e2e\e2e.options.logSnippet.js:31:33)
      at callFn (C:\wamp\www\browser-sync\node_modules\mocha\lib\runnable.js:249:21)
      at Test.Runnable.run (C:\wamp\www\browser-sync\node_modules\mocha\lib\runnable.js:242:7)
      at Runner.runTest (C:\wamp\www\browser-sync\node_modules\mocha\lib\runner.js:373:10)
      at C:\wamp\www\browser-sync\node_modules\mocha\lib\runner.js:451:12
      at next (C:\wamp\www\browser-sync\node_modules\mocha\lib\runner.js:298:14)
      at C:\wamp\www\browser-sync\node_modules\mocha\lib\runner.js:308:7
      at next (C:\wamp\www\browser-sync\node_modules\mocha\lib\runner.js:246:23)
      at Object._onImmediate (C:\wamp\www\browser-sync\node_modules\mocha\lib\runner.js:275:5)
      at processImmediate [as _immediateCallback] (timers.js:336:15)




npm ERR! browser-sync@1.5.1 unit: `mocha --recursive test/specs --reporter spec --timeout 10000`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the browser-sync@1.5.1 unit script.
npm ERR! This is most likely a problem with the browser-sync package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     mocha --recursive test/specs --reporter spec --timeout 10000
npm ERR! You can get their info via:
npm ERR!     npm owner ls browser-sync
npm ERR! There is likely additional logging output above.
npm ERR! System Windows_NT 6.2.9200
npm ERR! command "C:\\Program Files\\nodejs\\\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js"
 "run" "unit"
npm ERR! cwd C:\wamp\www\browser-sync
npm ERR! node -v v0.10.28
npm ERR! npm -v 1.4.9
npm ERR! code ELIFECYCLE
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR!     C:\wamp\www\browser-sync\npm-debug.log
npm ERR! not ok code 0


Other than that, the option works fine !