Query for applications that need to be provisioned.

Adds a method to the Applications domain class that can return a list of
UUIDs for applications that are ready to be provisioned. It requires
that:

- the associated portfolio and state machine have a state of COMPLETED
- the application not have been marked deleted
- the application not have an existing cloud_id
- the application does not have an existing claim on it

alembic/versions/07e0598199f6_add_applications_claimed_until.py

@@ -0,0 +1,30 @@
+"""add applications.claimed_until
+
+Revision ID: 07e0598199f6
+Revises: 26319c44a8d5
+Create Date: 2020-01-25 13:33:17.711548
+
+"""
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision = '07e0598199f6' # pragma: allowlist secret
+down_revision = '26319c44a8d5' # pragma: allowlist secret
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('applications', sa.Column('claimed_until', sa.TIMESTAMP(timezone=True), nullable=True))
+    op.add_column('applications', sa.Column('cloud_id', sa.String(), nullable=True))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('applications', 'claimed_until')
+    op.drop_column('applications', 'cloud_id')
+    # ### end Alembic commands ###