play auto-test may have bugs

[ikeike443]

When using play auto-test, some bugs were found:

• Though compilation error occurs, exit value that play returned was 0, so this jenkins plugin couldn't catch this error.
• Though port binding error occurs, exit value that play returned was 0, so this jenkins plugin couldn't catch this error.

[imeredith]

Hmm, I need to test this. I think we can do a precompile to check for compilation issues.