Sahara: editing licenses

Licenses in files base.py, test_plugins.py and
test_node_group_templates.py use different number of white spaces
than the others. This CR fixes that for consistency.

Files base.py, test_plugins.py and test_node_group_templates.py
have been created in 2014, however in their copyrights 2013 is written.
This CR fixes that.

Partially implements: blueprint savanna-api-tests

Change-Id: Id93b93acd10921f92540f64cc4e82e143454d3f4
Merge "Sahara: editing licenses"