Updated travis config to exclude Django2.x on python 2.7 and pypy
Updated travis config to exclude Django2.x on python 2.7 and pypy

Signed-off-by: Rolf Håvard Blindheim <6397d960c7f42bbf53f0004eee381be9e2936db8@gmail.com>

inonit/drf-haystack,jannon/drf-haystack