Switch cookiecutter tox job to use test_tox_targets.sh

This verifies that the thing we generate will actually pass its
defined tests. It's a superset of the tests we were running before.

Also adds git config calls to make this work in the gate where
the user details aren't already set.

Change-Id: I96810e7cf132304ca700ebedd0c43e3d4d56bbd4

tools/test_tox_targets.sh

@@ -18,6 +18,8 @@ cd $project_dir
 # PBR requires a git repo for versioning
 git init .
 # openstackdocstheme requires commits for last modified calculation
+git config user.email "test@example.com"
+git config user.name "Test Name"
 git add .
 git commit -m "Test commit"
 
@@ -28,4 +30,4 @@ def test_api():
     pass
 EOF
 
-tox -e pep8,py27,py36,py37,docs,lower-constraints,cover
+tox -e pep8,py27,py36,docs,lower-constraints,cover

tox.ini

@@ -6,5 +6,4 @@ skipsdist = True
 [testenv:cookiecutter]
 deps = cookiecutter
 commands =
-    mkdir -p {envdir}/tmp
-    {toxinidir}/tools/test_template.sh {envdir}/tmp
+    {toxinidir}/tools/test_tox_targets.sh