[Sqlalchemy-tickets] Issue #3386: Create engine with given dialect object (zzzeek/sqlalchemy)

[eirnym <iss...@bi...>]

New issue 3386: Create engine with given dialect object
https://bitbucket.org/zzzeek/sqlalchemy/issue/3386/create-engine-with-given-dialect-object

eirnym:

I want to have same dialect object for different engines (for example, main and mock), so I want to define dialect not only with url string, but also with specifying dialect object.

```
#!python
    primary_engine = create_engine(connect_url, **other_params)
    pass   # do something here
    mock_engine = create_engine(primary_engine.dialect, strategy=mock, executor=some_executor)
    # Or better to have something like this:
    mock_engine = create_mock_engine(primary_engine.dialect, executor=some_executor')
```

Now I have to care about which dialect I use like this:
```
#!python
    primary_engine = create_engine(connect_url, **other_params)
    pass   # do something here
    mock_engine = create_engine('postgres:///', strategy=mock, executor=some_executor)
```