Schemas

[deniszgonjanin]

This PR adds support for specifying database schemas when creating a new database source. I've tested it against redshift. It should address all or parts of the following: #336, #325, and #252, and #217.

To specify a schema, create a data source with the schema specified in the extras, like so:

{
    "metadata_params": {
          "schema":"myschema"
     },
    "engine_params": {
          "connect_args":{
        }
     }
}

Note that it does specify the schema right on the database source, and not on individual tables. I think this is preferable, so that you don't have to specify schemas on every table you create. You can also segment your database sources based on the schema you are using, which is probably what you want anyway.

[landscape-bot]

Code quality remained the same when pulling 76f1838 on deniszgonjanin:schemas into af417b6 on airbnb:master.

[coveralls]

Coverage increased (+0.06%) to 72.559% when pulling 76f1838 on deniszgonjanin:schemas into af417b6 on airbnb:master.

[mistercrunch]

#330 allows specifying the schema when adding the table