Add ability to set skipHeaders into the options to prevent the setting of HTTP header fields for X-RateLimit-Limit, X-RateLimit-Remaining and Retry-After.
Add ability to pass ignoreErrors to the configuration options.

When ignoreErrors is true, if an error is encountered connecting to redis the next() middleware is called.
Merge pull request #2 from roark31337/feature/skipHeaders

Add ability to set skipHeaders into the options to prevent the setting o...