Fixed invalid docblocks.
Added SensioInsights badge
Fixex getSize() to return false instead of null

Adhere to ReadInterface's contract to return false for not existing entries
Fixes #67: Zero sized files were never cached.
Update AbstractCache.php
Merge pull request #68 from staabm/patch-1

Fixed getSize() to return false instead of null
Return false instead of null as defined in ReadInterface
Rely on ReadInterface contract for getSize().

The return type in the cache impl was fixed recently, therefore we can rely on the contract
Merge pull request #70 from staabm/patch-2

Rely on ReadInterface contract for getSize().
Merge pull request #69 from staabm/patch-1

Return false instead of null as defined in ReadInterface