DDF-199: Added a Content Disposition header to the response to format the filename as <DDF_Sitename>_<Start_Date>_<End_Date>
DDF-199: Added a Content Disposition header to the response to format the filename as <DDF_Sitename>_<Start_Date>_<End_Date>. Updated unit tests.
Update MetricsEndpointTest.java
Merge branch 'master' of https://github.com/ysalzberg/ddf-platform