Add check-manifest

MANIFEST.in

@@ -6,4 +6,5 @@
 recursive-include cubicweb_elasticsearch/pviews/templates *.jinja2
 
 include test/data/bootstrap_cubes
+recursive-include test *.py
 include tox.ini
@@ -9,1 +10,4 @@
 include tox.ini
+include .gitlab-ci.yml
+prune debian
+prune cubicweb-elasticsearch.spec

tox.ini

 [tox]
-envlist = py27,flake8
+envlist = py27,flake8,check-manifest
 
 [tox:jenkins]
 envlist = py27,flake8-jenkins
@@ -33,3 +33,11 @@
 max-line-length = 100
 ignore = E731,W503
 exclude = cubicweb_elasticsearch/__pkginfo__.py,cubicweb_elasticsearch/migration/*,test/data/*,setup.py,.tox/*
+
+[testenv:check-manifest]
+skip_install = true
+skipsdist = true
+deps =
+  check-manifest
+commands =
+  {envpython} -m check_manifest