Upgrade StackExchange.Redis to v2.6.122 (#258)

Fix dependency doubleup (#210)

Minor benchmark updates

Merge pull request #196 from TurnerSoftware/detailed-cache-entry-status

Prevent returning expired entries

Merge pull request #193 from rgueldenpfennig/nullreferenceexception-o…

…n-concurrent-access

 NullReferenceException on blocked task when original task faulted

Merge pull request #188 from TurnerSoftware/fix-file-manifest-load-is…

…sues

Fix file manifest load issues

Use lambda/factory version of AddSingleton

This allows the service provider to correctly dispose of our cache stacks when the application is terminated.

Fixes #187

Reorganize RedisLockOptions properties

Some properties are only needed internally and the order now matches the constructor.

Update branch name

Additional error information from Redis for tests