added the "linters" tox target to tox.ini and to travis job

Author: brunobord

.travis.yml

@@ -9,6 +9,7 @@ env:
   - TOX_ENV=py35-django19
   - TOX_ENV=py27-django110
   - TOX_ENV=py35-django110
+  - TOX_ENV=linters
 install:
   - pip install tox
 script:

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    {py27,py35}-django{18,19,110}
+    {py27,py35}-django{18,19,110},linters
 
 [testenv]
 passenv = DATABASE_URL
@@ -14,3 +14,11 @@ deps =
     django-19: Django>=1.9,<1.10
     django-110: Django>=1.10,<1.11
     -r{toxinidir}/requirements_test.txt
+
+# Dedicated linter tox target
+[testenv:linters]
+deps =
+    # Does not need any other requirement
+    -r{toxinidir}/requirements_test.txt
+commands =
+    make lint