ENH: *_exists to exists
MAINT: Now raise UnknownAxisError
MAINT: Fix UnknownAxisError
MAINT: credits
MAINT: fix exists calls
Force travis run
MAINT: EXPLICIT DECLARATION OF axis
MAINT: EXPLICIT DECLARATION OF axis
merge conflicts resolved
MAINT: removal of explicit axis
Merge pull request #329 from squirrelo/exists

ENH: *_exists to exists