Remove logic for creating tables (#988)
Remove logic for creating tables (#988)

Removed logic for creating tables and a schema from the TensorBoard
application. The schema created by TensorBoard is out of date,
leading to errors that make TensorBoard fail to start up such as

```
    return f(*args[:-2] + (request,))(*args[-2:])
  File "/usr/home/chihuahua/Desktop/tensorboard/tensorboard/backend/application.py", line 243, in _serve_plugins_listing
    response[plugin.plugin_name] = plugin.is_active()
  File "/usr/home/chihuahua/Desktop/tensorboard/tensorboard/plugins/scalar/scalars_plugin.py", line 77, in is_active
    ''', (metadata.PLUGIN_NAME,))
  File "/usr/home/chihuahua/Desktop/tensorboard/tensorboard/db.py", line 505, in execute
    cursor.execute(sql, parameters)
  File "/usr/home/chihuahua/Desktop/tensorboard/tensorboard/db.py", line 572, in execute
    self._delegate.execute(sql, parameters)
OperationalError: no such column: Tags.plugin_name
```
qiuminxu/tensorboard,tensorflow/tensorboard,qiuminxu/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,qiuminxu/tensorboard,qiuminxu/tensorboard,tensorflow/tensorboard,qiuminxu/tensorboard,tensorflow/tensorboard,qiuminxu/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard