MAINT: Disable TravisCI git clone depth.
MAINT: Disable TravisCI git clone depth.

The default clone depth of TravisCI is 50, which is insufficient to make
the most recent annotated tag visible to versioneer now that master is
has grown to 579 commits past the tag. Disabling the clone depth as
suggested at https://docs.travis-ci.com/user/customizing-the-build/
appears to solve the problem.

endolith/numpy,numpy/numpy,mattip/numpy,madphysicist/numpy,anntzer/numpy,endolith/numpy,rgommers/numpy,pdebuyl/numpy,pdebuyl/numpy,pbrod/numpy,madphysicist/numpy,simongibbons/numpy,anntzer/numpy,mattip/numpy,simongibbons/numpy,mattip/numpy,jakirkham/numpy,rgommers/numpy,rgommers/numpy,pdebuyl/numpy,mhvk/numpy,numpy/numpy,seberg/numpy,anntzer/numpy,mhvk/numpy,charris/numpy,charris/numpy,madphysicist/numpy,pbrod/numpy,simongibbons/numpy,anntzer/numpy,seberg/numpy,pbrod/numpy,charris/numpy,jakirkham/numpy,madphysicist/numpy,numpy/numpy,endolith/numpy,pdebuyl/numpy,madphysicist/numpy,endolith/numpy,jakirkham/numpy,pbrod/numpy,numpy/numpy,seberg/numpy,seberg/numpy,mhvk/numpy,mhvk/numpy,simongibbons/numpy,simongibbons/numpy,mhvk/numpy,mattip/numpy,charris/numpy,rgommers/numpy,jakirkham/numpy,pbrod/numpy,jakirkham/numpy