tox.ini: force pip<8

tox.ini

@@ -22,9 +22,10 @@ commands =
     py.test {posargs} tests
 
 [testenv:package]
+# eobuilder is not on pypi, too bad
 install_command = pip install --pre --find-links https://jenkins.entrouvert.org/packages/ {opts} {packages}
 deps = setuptools
-  pip
+  pip<8
   eobuilder
 commands =
   sh -c "sudo -u eobuilder -E env HOME=/var/lib/eobuilder PATH=$PATH $VIRTUAL_ENV/bin/eobuilder-ctl -d wheezy,jessie `pwd`"