addtional user profile attributes
fixed request schema validation
fixed typo
adjusted user schema
added validation for "date" format (closes 51)
fixed track bulk upload with only a sensor referenced in the track
Merge branch 'dev'

* dev:
  fixed track bulk upload with only a sensor referenced in the track
  added validation for "date" format (closes #51)
  adjusted user schema
  fixed typo
  fixed request schema validation
  addtional user profile attributes