Update composer.json

Add `conflict` part as `doctrine/common` <2.4 has cache in it.
Merge pull request #2 from BenMorel/master

Documentation fixes
Added the branch alias for master
Merge pull request #4 from stof/patch-1

Added the branch alias for master
Fixed typo in constant (BC)
Merge pull request #5 from pborreli/typos

Fixed typo in constant (BC)
Add Changelog to README.md
Added check if Redis is compiled with igbinary support.
Merge pull request #7 from pkruithof/patch-1

[DCOM-128] Added check if Redis is compiled with igbinary support.
Merge pull request #1 from stloyd/patch-1

Update composer.json
Reducing number of redis operations when using expiration time for setting data
Merge pull request #9 from import/fix/redis-cache-performance

Redis cache performance improvement
implemented RiakCache.
Implemented support for flushAll as per php_riak 0.5.0 release (to happen yet on PECL). Still no support for HEAD operations (contains()).
provide stats for file caches
ignore 'local' phpunit config file
also test against php 5.5 on travis ci
Merge pull request #15 from nesQuick/filestats

provide stats for file caches
Merge pull request #13 from nesQuick/testagainstphp55

also test against php 5.5 on travis ci
Merge pull request #14 from nesQuick/phpunitconfigignore

ignore 'local' phpunit config file