Move oslo config generator config inside package

This commit moves the oslo config generator config file from living as
a data file, which makes it very difficult to rely on, to just living
in the package. By including it in the package we have a guaranteed
relative path we can rely on for building utilities on it, like the
tempest init command.

Change-Id: I5b9deae733f42fe3ed39418103304f71b43dccb3
Partially-implements: bp tempest-run-cmd
diff --git a/tox.ini b/tox.ini
index 44162fd..cff222d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -28,7 +28,7 @@
     bash tools/pretty_tox.sh '{posargs}'
 
 [testenv:genconfig]
-commands = oslo-config-generator --config-file etc/config-generator.tempest.conf
+commands = oslo-config-generator --config-file tempest/cmd/config-generator.tempest.conf
 
 [testenv:cover]
 setenv = OS_TEST_PATH=./tempest/tests