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
Merge branch 'issue_285' into issue_16
Merge branch 'issue_282' into issue_16
Merge branch 'issue_276' into issue_16