SQLite locking prevents creating access tokens while api-gateway is running

[bcongdon]

To reproduce:

1. Start the groot-api-gateway docker container
2. Run a second version of the api-gateway container with the -r command to try to create a new access token.
3. The operation fails, giving timeout as the error message.
   (Note that the both containers must share the same data volume to persist the clients.db file)

It seems like SQLite locks the database file, so it's not possible to create a new token while the api-gateway is running.

I feel like this is a bug with bolt, or our use of it. It might be due to how docker handles sharing files in volumes between containers, I haven't tried to do this locally.

[narendasan]

Look at leveldb