v0.8.0

• Fix the issue of parameter concatenation when generating ORM with inspectdb (#331)
• Fix KeyError when deleting a field with unqiue=True. (#364)
• Correct the click import. (#360)
• Improve CLI help text and output. (#355)
• Fix mysql drop unique index raises OperationalError. (#346)
  Upgrade note:
  1. Use column name as unique key name for mysql
  2. Drop support for Python3.7