Rename hashmap mapping table to hashmap_mappings

Improve naming consistency across all tables.
Will improve constraint naming conventions.

Change-Id: Iede49da21e73dabbd4086261984bba4b082211f8

cloudkitty/rating/hash/db/sqlalchemy/alembic/versions/10d2738b67df_rename_mapping_table_to_hashmap_mappings.py

@@ -0,0 +1,21 @@
+"""Rename mapping table to hashmap_mappings.
+
+Revision ID: 10d2738b67df
+Revises: 54cc17accf2c
+Create Date: 2016-05-24 18:37:25.305430
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '10d2738b67df'
+down_revision = '54cc17accf2c'
+
+from alembic import op
+
+
+def upgrade():
+    op.rename_table('hashmap_maps', 'hashmap_mappings')
+
+
+def downgrade():
+    op.rename_table('hashmap_mappings', 'hashmap_maps')

cloudkitty/rating/hash/db/sqlalchemy/models.py

@@ -201,7 +201,7 @@ class HashMapMapping(Base, HashMapBase):
 
     Used to model final equation.
     """
-    __tablename__ = 'hashmap_maps'
+    __tablename__ = 'hashmap_mappings'
     fk_to_resolve = {
         'service_id': 'service.service_id',
         'field_id': 'field.field_id',