Merge pull request #342 from pre-commit/latest_virtualenv_breaks_tests

Workaround pypa/pip#3461

.travis.yml

@@ -8,7 +8,9 @@ env: # These should match the tox env list
     - TOXENV=pypy
     - TOXENV=pypy3
     - TOXENV=py27 LATEST_GIT=1
-install: pip install coveralls tox
+# latest virtualenv combined with downgrading setuptools = sadness
+# https://github.com/pypa/pip/issues/3461
+install: pip install coveralls tox 'virtualenv<14'
 script: tox
 # Special snowflake.  Our tests depend on making real commits.
 before_install:

requirements-dev.txt

@@ -9,3 +9,7 @@ pytest
 
 # setuptools breaks pypy3 with extraneous output
 setuptools<18.5
+
+# latest virtualenv combined with downgrading setuptools = sadness
+# https://github.com/pypa/pip/issues/3461
+virtualenv<14