Update model

- adds email_from field to the service model
- adds subject_line to the template model

These are unique and not null fields, so there is a migration here for email_from to populate it.

migrations/versions/0016_add_email_from.py

@@ -0,0 +1,23 @@
+"""empty message
+
+Revision ID: 0016_add_email_from
+Revises: 0015_add_subject_line
+Create Date: 2016-02-18 11:25:37.915137
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '0016_add_email_from'
+down_revision = '0015_add_subject_line'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.add_column('services', sa.Column('email_from', sa.Text(), nullable=True))
+    op.execute("UPDATE services SET email_from=name")
+
+
+def downgrade():
+    op.drop_column('services', 'email_from')