Fixed pep8 test fails introduced by pep8 v1.50.
Merge pull request #1080 from pp-mo/pep8_1v50

Fixed pep8 test fails introduced by pep8 v1.50.
cube math broadcasting
ENH: Tests for cube broadcasting.
Mods to cpelley tests
Fixed issue with broadcasting of masked arrays
refactor
Test tidy up
Move to masked testing
Added slice tests
Fixed headers
Review actions
Removed redundant broadcasting tests