made Pool an interface (pool)

[JavierZunzunegui]

As it stands having Mutex.nodes as a struct array ([]*redis.Pool) limits the use of this library as it can't be adapted to our more specific pools.

[hjr265]

Hi Javier,

Thanks for creating this pull request.

I might be missing something here, but does reducing the Pool type's visibility help here? I think it kind of makes the NewMutexWithPool func unusable from other packages.

https://github.com/golang/go/wiki/InterfaceSlice

So []*redis.Pool will not satisfy that argument's type, since it expects an array of a particular interface. Unless it is possible to construct an array of redsync.Pool from other packages, there won't be much use for NewMutexWithPool func.

It may be a good idea to create a separate func for this as others may already be relying on the current ones and I do not want to abruptly break compatibility for them.

Best regards,
Ridwan

[JavierZunzunegui]

Hi Ridwan,
Just noticed what your point, reverted my visibility changes. Also will commit in a minute a different NewMutexWithPool that maintains backwards compatibility.

[hjr265]

@JavierZunzunegui Thank you!