fixes #153: naming conflict when using Connection suffix

[tomahim]

I propose to fix the #153 issue by renaming all connection classes with the suffix Connection as it seems to be use by the graphene_reducer.

The suffix Conn may not be great, I'm open to other suggestions 😄

[coveralls]

Coverage remained the same at 91.854% when pulling 0b4c0c6 on tomahim:fix/153-flask_sqlalchemy-example-employee-connection-naming-conflict into 8872577 on graphql-python:master.

[swuecho]

thanks! saved my day.

[mfrlin]

This has been already fixed.

[jnak]

The issue has not been fixed in the sense that it does not need to be fixed. The way to workaround this is to avoid defining Connection for types. If you need to refer to those connections, you can access it with YourType._meta.connection. Eventually, we should expose a way to get it without accessing a private attribute.

Closing this since this is not correct approach.

[jnak]

See #153 (comment) for more context