feat: Flatten files option according to grunt plugin standard.
Merge pull request #104 from cgross/master

flatten files option as typical in grunt plugins
chore: Release 0.8.3
chore: Pass Node versions as strings to Travis

Node versions, as most versions, are strings, not numbers. 0.10 as a number
equals 0.1 which by the virtue of nvm is matched as 0.10 but shouldn't be
relied upon. Also, it screws Node numbering in Travis runs, see e.g.:
https://travis-ci.org/karma-runner/grunt-karma/builds/28585432
Merge pull request #118 from mzgol/travis-node-version

chore: Pass Node versions as strings to Travis
Temporarily remove uncaughtException listeners.

Remove these listeners while Karma is running, so that Karma gets a
chance to stop the browsers it started, in case a framework raises
an error or the user presses Ctrl-C.

fixes #93
Listen for SIGINT and stop the process.

Karma listens for SIGINT and disconnects all servers if interrupted.
As a side-effect, interrupting the current process causes Karma to stop
but nothing else. Any pending Grunt tasks will still run.

Since Grunt does not listen to SIGINT itself, the expected behaviour
is that the process exits with code 130. We simulate this by listening
for SIGINT and calling process.exit() when Karma finished.