APEX integration with travis-ci and 4MB log limit

[Vlad Rozov]

Travis-ci has 4 MB limit on the build log and APEX core "mvn test" 
produces around 3.7 MB of output. We will not be able to add more unit 
tests to the project unless we reduce verbosity of the output. Changing 
log level is one of possible solutions, though it may not be the best 
one as it will be harder to troubleshoot test failures in the travis-ci 
environment. I suggest that we put some effort here before the limit is 
reached.

Vlad