Merge pull request #538 in CASA/casa6 from CAS-12228 to master
* commit '20b92d809c001d6463ca7472e60a0c38696168e3':
Refactored test_spwSelection(0 to use msmd methods. Removed the showcache from tearDown.
Added a header to test_task_exportuvfits. Updated the component json map file with the new test. Light refactoring of two test cases
modified the spw selection test case
more reformatting of test case names
re-formatted removed suite function removed futures imports
added more doc strings and removed commented code
renamed test_exportuvfits to test_req_task_exportuvfits
added new test cases to exportuvfits
