Merge branch 'develop'

* develop: (41 commits)
  ALM-651 small formatting changes
  ALM-651 convert retrieval_history events into monthly events
  ALM-652 API error is symbol not string
  ALM-652 fixed caching tests
  ALM-623 test that subcategories have changed
  ALM-653 added retrieval_history model back in for migrating data
  ALM-652 API error is a symbol not string
  ALM-652 changed default attributes for v4 and v5 API
  ALM-652 changed default attributes for v4 and v5 API
  ALM-623 handle missing attributes gracefully
  ALM-623 handle missing event_metrics
  ALM-652 don't handle NoMethodError
  proper hash formatting in factory
  ALM-652 added tests for v5 API
  ALM-623 renamed expected subcategories in rspec test
  ALM-652 rename rabl attribute
  ALM-652 renamed rabl attribute
  ALM-652 added default hash for event_metrics in decorator
  ALM-623 reorganize subcategories for v5 API
  ALM-652 simplified decorator for retrieval_status
  ...
Add in the success path too
Extend possible intervals.
Change PubMed to include 'Central' in the names displayed. and put europe in the right place

also change descrip. of Database to change 'literature' to 'data'...
Tidy up description further
Merge pull request #64 from rivimey/feature/api-docs-v4

Additional description of v4 api and how to use it.
Merge pull request #63 from rivimey/feature/pubmed_displayed_names

Change PubMed display names to match official versions.
Merge pull request #65 from rivimey/feature/additional-intervals

Extend possible intervals.
Adjust strings to '' from ""  & limit line lengths to make houndci happier
Merge pull request #66 from rivimey/feature/string-style-tidy

Adjust strings from ""  to '' and limit line lengths so houndci is happier
Use \ instead of + to concatenate lines to be consistent with Ruby style guide. Closes #66.
ALM-673 added rack-mini-profiler gem
ALM-673 changed syntax for admin check
ALM-652 updated documentation for v5 API, depreciated v3 API
Merge branch 'master' into develop

* master:
  ALM-652 updated documentation for v5 API, depreciated v3 API
  ALM-673 changed syntax for admin check
  ALM-673 added rack-mini-profiler gem
  Use \ instead of + to concatenate lines to be consistent with Ruby style guide. Closes #66.
  Adjust strings to '' from ""  & limit line lengths to make houndci happier
  Tidy up description further
  Change PubMed to include 'Central' in the names displayed. and put europe in the right place
  Extend possible intervals.
  Add in the success path too