Allow mmo init to declare the module path

[petomalina]

This feature should allow users to initialize the project with gomod path instead of using just the project name.

Proposed changes:

go mod init github.com/flowup/something

Will initialize a new directory named something in the current path and initialize go.mod to github.com/flowup/something. This will enable us to initialize go mod outside of the GOPATH.

@bafko @kubaj what do you guys think about this?

We may also remove prefix from the mmo.yaml as it will be supplied by the go.mod