Update schema and create/update Environments domain methods to enforce environment name uniqueness within an application context.

alembic/versions/08f2a640e9c2_add_uniqueness_contraint_to_environment_.py

@@ -0,0 +1,28 @@
+"""add uniqueness contraint to environment within an application
+
+Revision ID: 08f2a640e9c2
+Revises: c487d91f1a26
+Create Date: 2019-12-16 10:43:12.331095
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = '08f2a640e9c2' # pragma: allowlist secret
+down_revision = 'c487d91f1a26' # pragma: allowlist secret
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_unique_constraint('environments_name_application_id_key', 'environments', ['name', 'application_id'])
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_constraint('environments_name_application_id_key', 'environments', type_='unique')
+    # ### end Alembic commands ###