new_contents: """Drop Trackman tables
  
  Revision ID: 5981b26ae993
  Revises: 804fb3dc434f
  Create Date: 2018-05-19 23:57:42.897891
  
  """
  
  # revision identifiers, used by Alembic.
  revision = '5981b26ae993'
  down_revision = '804fb3dc434f'
  
  from alembic import op
  import sqlalchemy as sa
  
  
  def upgrade():
      op.drop_table('air_log')
      op.drop_table('tracklog')
      op.drop_table('trackreport')
      op.drop_table('track')
      op.drop_table('djset')
      op.drop_table('dj')
      op.drop_table('rotation')
  
  
  def downgrade():
      raise Exception("Downgrade to previous versions is unsupported.")
  
subject: Add migration to drop Trackman tables