Remove oboe_fu artifacts.
Updated SWIG from tracelytics/oboe#206
Change keyname to RubyHeroku.Oboe.Version
Include constants and accessors for bit masks
Extract sample_rate and sample_source when available
Report liboboe returned sample rate/source
Include more liboboe constants and change r to rv
On initialization, set all values manually
Remove test for a default sample_source - liboboe handles that.
Don't initialize sample_rate at all since it's not required in any case.
Tests to validate SampleSource on localset
Don't set sample rate/source manually.  Rely entirely on liboboe.
Only report SampleRate/Source when tracing_mode == always
Add json as a runtime dependency
Merge pull request #276 from tracelytics/issue_276

Remove oboe_fu artifacts
Merge pull request #285 from tracelytics/issue_285

Change OboeHeroku __Init Key
Merge pull request #282 from tracelytics/issue_282

Report SampleRate & SampleSource per updated SWIG API
Merge remote-tracking branch 'public/master'
Merge branch 'master' into issue_11

Conflicts:
	oboe.gemspec
Merge pull request #11 from appneta/issue_11

oboe.gemspec doesn't specify Ruby 1.8 json dependency