added display_label facility to survey questions
added last-negative field to surveyquestion to support categories like wait time
fixed wait time migration
added positive_response field to SurveyQuestionResponse model. This helps de-normalize for reporting and to insulate results from changes in questions.
added last_required field to surveyquestion to help determine when survey is completed.
fixed data migration for positive response and added tests
added field for questions that are used for calculation of satisfaction indices
added fields for satisfaction and participation to clinics models + migrations. this is to de-normalise the tables and allow for de-coupling of textit questions from statistics
completed de-normalisation of satisfaction and participation
The calculation of satisfaction and participation has been broken down into 2 steps:
1. determination of satisfaction index and participation when a survey response is saved.
2. trivial aggregation of denormalised data
Next is the implementation in the reports to take advantage of the new de-normalised structure
added dependency on survey to datamigration
Merge pull request #225 from myvoice-nigeria/textit-questions

Textit questions
added display_label and survey_question
Merge pull request #226 from myvoice-nigeria/survey-admin

added display_label and survey_question
Remove max_length for GenericFeedback message
Test for long feedback
Shorten test for long feedback
Merge pull request #227 from myvoice-nigeria/long-feedback

Allow long feedback