corrected multiple visit error message
added acceptable answers to modes for wait_time and updated test
get_mode does basic conversion of "hour" to "hr"
fixed failing test
Merge branch 'hour-hr' into small-changes

merged hour-hr and duplicate-visit to small-changes
added period as delimiter
added start to list of feedback not to be displayed
added field sender to visit model to keep sender information. updated tests, added migration
filter blocked numbers from getting surveys
prevent generic feedback from being saved by visit.sender
Merge branch 'block-numbers' into small-changes

merging with block-numbers so I can deploy to staging
removed unused import
Merge pull request #204 from caktus/small-changes

Small changes