Fixes LP Bug#899383 - Cleanup config file search

Cleans up a bunch of configuration-related errors
when trying to run tempest out of the box with a
simple call to:

$> nosetests storm

* Raises a sensible error if the config file cannot be found
* Makes it possible to set the config file directory and
  config file name via environment variables
* Removes unnecessary calls to create storm.config.StormConfig()
  and share a configuration object by passing the openstack.Manager's
  config object with the various rest client objects
* Updates the README to show how to make a config file and run
  the tests in tempest

Change-Id: I60e33595b88df596cc9585bcaf18d37ae77d6f2b
diff --git a/.gitignore b/.gitignore
index 4ed762e..9355e87 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,10 @@
 .kong-venv
 *.pyc
 etc/config.ini
+etc/storm.conf
+etc/tempest.conf
 include/swift_objects/swift_small
 include/swift_objects/swift_medium
 include/swift_objects/swift_large
 *.log
+*.swp