Merge pull request #18 from jdjkelly/staging

Moved sync to user#show
CircleCI bombs on these without requiring them
Fixed bad commit
Merge pull request #21 from jdjkelly/staging

Staging
Merge pull request #23 from jdjkelly/staging

Staging
Merge pull request #25 from jdjkelly/staging

Improved unit support - splitting Unit.to into Unit.to_unit
Merge pull request #27 from jdjkelly/staging

Ruby 2.1
Merge pull request #30 from jdjkelly/staging

Fitbit Sleep data
Hotfix for sleeps, syncing data
Resolved broken tests
Instead of calling .try(), we should check that the provider exists - otherwise this could bury valuable errors