Add model class and migration script for invited user.

migrations/versions/0022_add_invite_users.py

@@ -0,0 +1,42 @@
+"""empty message
+
+Revision ID: 0022_add_invite_users
+Revises: 0021_add_job_metadata
+Create Date: 2016-02-23 16:41:40.481468
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '0022_add_invite_users'
+down_revision = '0021_add_job_metadata'
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+def upgrade():
+    ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('invited_users',
+    sa.Column('id', postgresql.UUID(as_uuid=True), nullable=False),
+    sa.Column('email_address', sa.String(length=255), nullable=False),
+    sa.Column('user_id', sa.Integer(), nullable=False),
+    sa.Column('service_id', postgresql.UUID(as_uuid=True), nullable=True),
+    sa.Column('_token', sa.String(), nullable=False),
+    sa.Column('created_at', sa.DateTime(), nullable=False),
+    sa.Column('status', sa.Enum('pending', 'accepted', 'cancelled', name='invited_users_status_types'), nullable=False),
+    sa.ForeignKeyConstraint(['service_id'], ['services.id'], ),
+    sa.ForeignKeyConstraint(['user_id'], ['users.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_invited_users_service_id'), 'invited_users', ['service_id'], unique=False)
+    op.create_index(op.f('ix_invited_users_user_id'), 'invited_users', ['user_id'], unique=False)
+    ### end Alembic commands ###
+
+
+def downgrade():
+    ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_invited_users_user_id'), table_name='invited_users')
+    op.drop_index(op.f('ix_invited_users_service_id'), table_name='invited_users')
+    op.drop_table('invited_users')
+    op.execute('DROP TYPE invited_users_status_types')
+    ### end Alembic commands ###