Tidy up - Rename Base

Some Python class and packages need to be renamed
for a better compliance with the shared terminology
which provides a better understanding of Watcher
objects and components by every contributor.

This patchset add missing Base in class name

Partially implements: blueprint glossary-related-refactoring

Change-Id: I95a3e41fbd5fcd90a99d81c9cf278940f50c7732

watcher/db/sqlalchemy/api.py

@@ -102,7 +102,7 @@ def _paginate_query(model, limit=None, marker=None, sort_key=None,
     return query.all()
 
 
-class Connection(api.Connection):
+class Connection(api.BaseConnection):
     """SqlAlchemy connection."""
 
     def __init__(self):