[build] setting sourceCompatibility and targetCompatiblity to 1.6
Incorrect casting of long to double

- Fixes #84
Updated CHANGELOG

- Version number in build.gradle
Add 'eid' to be generated for each event

- Initially, we added the eid to Subject class. When we created a
  tracking event it would only add an eid if you created a Subject.
  Along with that, the eid is only generated once and then reused in
  several events sent - we do not want this. Generating the eid in
  `completePayload` solves both of these issues for us.
- Fixes #95
Update CHANGELOG
Fix typo
Merge branch 'dstendardi-master'
Merge branch 'czchen-bugfix/typo2'
Merge branch 'hotfix/0.1.4'
Finalized CHANGELOG for Core 0.1.4
Updated auto-generated Version