Added "flag" function for stampede protection
It's -> Its
[Cache] Changing CacheItem::flag() to CacheItem::isRegenerating()
[Cache] Changing CacheItem::flag() to CacheItem::isRegenerating()
Merge pull request #16 from dragoonis/cache-stampede-prevention

Cache stampede prevention - CacheItem::isRegenerating()
Merge pull request #304 from tedivm/cache-stampede-prevention

[PSR-6] Added "CacheItem::isRegenerating()" function for stampede protection