Remove pypy target from master

pypy is 2.5.0, which is compatible with Python 2.7.13.
pypy3 is 2.4.0, which is compatible with Python 3.2, and won't work with
pip.

.travis.yml

@@ -46,8 +46,6 @@ matrix:
       python: "3.5"
     - env: TOXENV=py36-django111
       python: "3.6"
-    - env: TOXENV=pypy-django-master
-      python: "pypy"
     - env: TOXENV=py34-django-master
       python: "3.4"
     - env: TOXENV=py35-django-master
@@ -57,7 +55,6 @@ matrix:
     - env: TOXENV=docs
       python: "2.7"
   allow_failures:
-    - env: TOXENV=pypy-django-master
     - env: TOXENV=py34-django-master
     - env: TOXENV=py35-django-master
     - env: TOXENV=py36-django-master

tox.ini

 [tox]
 envlist =
-  {py27,py34}-django{16,17,18,19,110,111}
-  pypy-django{16,17,18,19,110,111,-master}
+  {py27,pypy,py34}-django{16,17,18,19,110,111}
   py35-django{19,110,111,-master}
   py36-django{111,-master}
   docs