Ensured that gcov coverage can only be enabled when using GCC.

Change-Id: I0f8c3092fe4a756a4b3dd650535b2c452da3c4ac
Changed Coveralls to exclude non-testing directories.
Ensure that we're using GCC before submitting to coveralls.
Added square braces around conditional.
Revert "Ensure that we're using GCC before submitting to coveralls."

This reverts commit 4725265e24dc0dadec03551b6c8ca1e124a86cc7.

Conflicts:
	.travis.yml
Merge branch 'coveralls'

Change-Id: I9bdd2f682aedee20c58947f188ec466f54adfb79
Merge branch 'coveralls-badge'

Change-Id: I202a61209062b4131c783c805d26bd69afa912f3