Add permission for internet access

Add in permission to allow cucumber/calabash to run app via a test
server.
Update .gitignore

Add calabash-specific files and folders to ignore.
Add in calabash

Calabash is a testing framework that uses cucumber for acceptance
testing on Android (see http://calaba.sh). Once installed, ensure that the
Android SDK is in the path and run `calabash-android run <apk>` in
\calabash.