no mechanism for clear _pendingResponses

[himulawang]

Hi,

I find there is no mechanism to clear _pendingResponses.

After RedisClient is connected and if it never closed, _pendingResponses in _RedisConnection will become longer and longer.

Now this lib is not suitable for any long time running app.

[andreleblanc-wf]

is this still a problem? it appears to be addressed by this commit:

a7f8c49