Correct env variable in file oslo.config.generator.rc

Use CEILOMETER_CONFIG_GENERATOR_EXTRA_MODULES as the environment
variable to include keystoneclient middleware's option in the config
generator's output.

Change-Id: Ibddeb587b22a0569dcb8db58d7cd8626b4482cb6
Closes-Bug: 1262331
Don't assume alarms are returned in insert order

The previous implentation of the tests assure than the db backends
return the alarms into the insert order. This is false for mysql.

The patch rewritte the tests to make it compatible to mysql

Change-Id: I146de0d8cef78b6c734bc6742238b939422645b9
Merge "Don't assume alarms are returned in insert order"