* provider/mysql: User Resource
This commit introduces a mysql_user resource. It includes basic
functionality of adding a user@host along with a password.
* provider/mysql: Grant Resource
This commit introduces a mysql_grant resource. It can grant a set
of privileges to a user against a whole database.
* provider/mysql: Adding documentation for user and grant resources
There are currently no checks on username and endpoint in the provider
schema from being an empty value. This PR adds support to make sure that
endpoint and username are not empty strings as that can cause a panic
Results of the PR:
```
% terraform apply
There are warnings and/or errors related to your configuration. Please
fix these before continuing.
Errors:
* provider.mysql: Endpoint must not be an empty string
```
protomouse