Stop running flake8 and isort as part of tox since they are now run as part of pre-commit

Author: Daniel Gallagher

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = flake8,isort,py27,py34,py35,py36,pre-commit,pypy,docs
+envlist = py27,py34,py35,py36,pre-commit,pypy,docs
 
 [testenv]
 deps =
@@ -22,17 +22,6 @@ setenv =
 commands =
     pre-commit {posargs:run --all-files}
 
-[testenv:flake8]
-deps = flake8
-commands = flake8
-
-[testenv:isort]
-basepython=python3.5
-deps =
-    isort==3.9.6
-    gevent==1.1rc1
-commands = isort -rc graphql
-
 [testenv:docs]
 changedir = docs
 deps = sphinx