Update .travis.yml

Split Travis test execution into combination of debug/release and core_only on/off.
Update .travis.yml

Fix the order of script
Update .travis.yml

Fix script
Fix linker errors in debug mode on Linux
Update .travis.yml

Run the unit tests only if "BUILD_CORE_ONLY" option is OFF
Update .travis.yml

Fix typo
Style fix
Merge branch 'origin/master'

Conflicts:
	unittests/CMakeLists.txt