add alembic migration script for vcf_release col

alembic/versions/2c00861f3ff1_vcfs_store_inferred_ensembl_release.py

@@ -0,0 +1,26 @@
+"""vcfs: store inferred ENSEMBL release
+
+Revision ID: 2c00861f3ff1
+Revises: 
+Create Date: 2015-08-31 17:50:09.263094
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '2c00861f3ff1'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    op.add_column('vcfs', sa.Column('vcf_release', sa.Integer))
+    pass
+
+
+def downgrade():
+    op.drop_column('vcfs', 'vcf_release')
+    pass