Upgrade setuptools in Travis so urllib3-1.18 installs
Upgrade setuptools in Travis so urllib3-1.18 installs

The version of setuptools in Travis is too old to handle <= as an
environment marker.

Signed-off-by: Jeremy Cline <b3f594e10a9edcf5413cf1190121d45078c62290@jcline.org>

barseghyanartur/django-haystack,barseghyanartur/django-haystack,elishowk/django-haystack,barseghyanartur/django-haystack,celerityweb/django-haystack,elishowk/django-haystack,celerityweb/django-haystack,sgaist/django-haystack,sgaist/django-haystack,sgaist/django-haystack,celerityweb/django-haystack,elishowk/django-haystack