Error 11-03-2018

(venv) dongocanh96@dongocanh96-ProBook-450:~/Workspace/class_manager$ flask db migrate -m "Teacher table"
/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/flask_sqlalchemy/__init__.py:794: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and will be disabled by default in the future.  Set it to True or False to suppress this warning.
  'SQLALCHEMY_TRACK_MODIFICATIONS adds significant overhead and '
Traceback (most recent call last):
  File "/home/dongocanh96/Workspace/class_manager/venv/bin/flask", line 11, in <module>
    sys.exit(main())
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/flask/cli.py", line 894, in main
    cli.main(args=args, prog_name=name)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/flask/cli.py", line 557, in main
    return super(FlaskGroup, self).main(*args, **kwargs)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/flask/cli.py", line 412, in decorator
    return __ctx.invoke(f, *args, **kwargs)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/flask_migrate/cli.py", line 90, in migrate
    rev_id, x_arg)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/flask_migrate/__init__.py", line 95, in wrapped
    f(*args, **kwargs)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/flask_migrate/__init__.py", line 215, in migrate
    version_path=version_path, rev_id=rev_id)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/alembic/command.py", line 176, in revision
    script_directory.run_env()
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/alembic/script/base.py", line 427, in run_env
    util.load_python_file(self.dir, 'env.py')
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/alembic/util/pyfiles.py", line 81, in load_python_file
    module = load_module_py(module_id, path)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/alembic/util/compat.py", line 82, in load_module_py
    spec.loader.exec_module(module)
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "migrations/env.py", line 87, in <module>
    run_migrations_online()
  File "migrations/env.py", line 70, in run_migrations_online
    poolclass=pool.NullPool)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/sqlalchemy/engine/__init__.py", line 466, in engine_from_config
    return create_engine(url, **options)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/sqlalchemy/engine/__init__.py", line 425, in create_engine
    return strategy.create(*args, **kwargs)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/sqlalchemy/engine/strategies.py", line 57, in create
    entrypoint = u._get_entrypoint()
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/sqlalchemy/engine/url.py", line 156, in _get_entrypoint
    cls = registry.load(name)
  File "/home/dongocanh96/Workspace/class_manager/venv/lib/python3.6/site-packages/sqlalchemy/util/langhelpers.py", line 221, in load
    (self.group, name))
sqlalchemy.exc.NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:slite