Add a keep option per fetch, fixes #60

admin/migrations/versions/3f6994568962_.py

@@ -0,0 +1,32 @@
+""" Add keep as an option in fetches
+
+Revision ID: 3f6994568962
+Revises: 2335c80a6bc3
+Create Date: 2017-02-02 22:31:00.719703
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '3f6994568962'
+down_revision = '2335c80a6bc3'
+
+from alembic import op
+import sqlalchemy as sa
+
+from mailu import app, db
+from mailu.admin import models
+
+
+def upgrade():
+    op.add_column('fetch', sa.Column('keep', sa.Boolean(), nullable=False, server_default=sa.sql.expression.false()))
+    # also apply the current config value if set
+    if app.config.get("FETCHMAIL_KEEP", "False") == "True":
+        for fetch in models.Fetch.query.all():
+            fetch.keep = True
+        db.session.commit()
+
+
+
+def downgrade():
+    with op.batch_alter_table('fetch') as batch:
+        batch.drop_column('keep')