[tox] add check-manifest

MANIFEST.in

@@ -6,4 +6,5 @@ recursive-include cubicweb_expense/data *.gif *.png *.ico *.css *.js
 recursive-include cubicweb_expense/i18n *.po *.pot
 recursive-include test/data bootstrap_cubes *.py
 include *.ini
-recursive-include debian changelog compat control copyright rules
+prune debian
+include *.txt

tox.ini

 [tox]
-envlist = py27,py3,flake8
+envlist = py27,py3,flake8,check-manifest
 
 [testenv]
 deps =
@@ -23,3 +23,10 @@ commands =
 [flake8]
 max-line-length = 120
 exclude = cubicweb_expense/migration/*,.tox/*,
+
+[testenv:check-manifest]
+skip_install = true
+deps =
+  check-manifest
+commands =
+  {envpython} -m check_manifest