aurweb.db: add query, create, delete helpers

Takes sqlalchemy kwargs or stanzas:

query(Model, Model.Column == value)
query(Model, and_(Model.Column == value, Model.Column != "BAD!"))

Updated tests to reflect the new utility and a comment about upcoming
function deprecation is added to get_account_type().

From here on, phase out the use of get_account_type().

+ aurweb.db: Added create utility function
+ aurweb.db: Added delete utility function

The `delete` function can be used to delete a record by search
kwargs directly.

Example:
    delete(User, User.ID == 6)

All three functions added in this commit are typically useful to
perform these operations without having to import aurweb.db.session.
Removes a bit of redundancy overall.

Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/db.py

@@ -11,6 +11,24 @@ Session = None
 session = None
 
 
+def query(model, *args, **kwargs):
+    return session.query(model).filter(*args, **kwargs)
+
+
+def create(model, *args, **kwargs):
+    instance = model(*args, **kwargs)
+    session.add(instance)
+    session.commit()
+    return instance
+
+
+def delete(model, *args, **kwargs):
+    instance = session.query(model).filter(*args, **kwargs)
+    for record in instance:
+        session.delete(record)
+    session.commit()
+
+
 def get_sqlalchemy_url():
     """
     Build an SQLAlchemy for use with create_engine based on the aurweb configuration.