Uncomment Clone method that was definitely commented by mistake

[yehor-manzhula]

It seems that a typo was made, and at the moment it's just impossible to clone session that is strongly affect performance.
@xiam Could you please take a look at it?

[xiam]

@egor-manjula good finding! I'll review/merge as soon as I fix travis.

[xiam]

@egor-manjula travis is fixed now, could you elaborate a bit more on the performance problems you're experimenting and how does Clone() fix them? Also please make sure CI is passing.

[yehor-manzhula]

@xiam Clone method allows to clone already existing session to new one without connecting to database once again that is why without such method each request need to reconnect to db to have its own session, that takes additional time - that is what I meant under performance issue.

[xiam]

@egor-manjula It's not necessary to reconnect to the database frequently, we usually work with one long running session (you can put the session on a package and export it), each session manages its own pool of connections. Can you try to use one exported session? If that does not solve your case, please elaborate a bit more on why you need to reconnect so often.

[yehor-manzhula]

@xiam Using package variable is not the case I want get. There is discussion on that here:
https://github.com/go-mgo/mgo/issues/287

In few words I want to Clone session on middleware layer, that session that is already in package variable.