Merge tag '2.1.4' into develop

- Added support for new Historics field 'estimated_completion'.
- Made API requests default to using SSL.
- Modified Historics the 'sample' param.
add missing $user parameter
Merge pull request #22 from raventools/develop

add missing $user parameter
fix parse errors
Merge pull request #23 from raventools/develop

fix parse errors
Fixed typo in consume-stream example
Merge pull request #24 from datasift/feature/fix-consume-stream-typo

Fixed typo in consume-stream example
Bumped to v.2.1.5
Merge branch 'release/2.1.5'