support more modules test by travis

[jixuan1989]

Because travis limits the size of console output, all modules except the cli are omitted by travis.yml.

We have to modify the UT codes by replacing System,out with logger.info to control the output.

[MyXOF]

Also, travis offers limited memory resources, some tests can not run normally.

[wujysh]

Maybe we should group test cases by priorities (P0, P1, P2, etc.), and only run the the most important ones (P0) on Travis CI.