Convert animas boluses to what tideline wants

This adds a source-specific conversion of boluses to what tideline wants.  This isn't the way it "should" be done, but until we actually have a well-defined storage format, this is how it will get to be done.
Merge branch 'master' into cheddar/convert-diasend-extended-bolus
Merge pull request #48 from tidepool-org/cheddar/convert-diasend-extended-bolus

Convert animas boluses to what tideline wants
Merge branch 'master' into stringify-data