Rename the Session class to Database

This feels way more natural; you don't have sessions with session properties
anymore.

Signed-off-by: Petr Šabata <contyk@redhat.com>

rida.py

@@ -46,7 +46,7 @@ app.config.from_envvar("RIDA_SETTINGS", silent=True)
 
 # TODO: Load the config file from environment
 conf = config.from_file("rida.conf")
-db = database.Session()
+db = database.Database()
 
 @app.route("/rida/module-builds/", methods=["POST"])
 def submit_build():

rida/database.py

@@ -31,7 +31,7 @@ from sqlalchemy.ext.declarative import declarative_base
 
 Base = declarative_base()
 
-class Session(object):
+class Database(object):
     """Class for handling database connections."""
 
     def __init__(self, rdburl=None):