add Master, ClockService UT and minor bug fix
Merge pull request #144 from huafengw/test

add Master, ClockService UT and minor bug fix
Metrics bug fix
Merge pull request #147 from huafengw/metrics

Fix Metrics bug(reporting metrics as zero) when sampleRate is set to value bigger than 1.
Reverting to be Java 6 compatible
Merge pull request #149 from smarthi/master

Reverting to be Java 6 compatible
Fixes #145
Merge pull request #150 from kkasravi/issue_145

Fixes #145