Support any version of Symfony 2.3-2.x (fixes #20)
Support any version of Symfony 2.3-2.x (fixes #20)

fesor/commonmark,garethellis36/commonmark,stof/commonmark,kkiernan/commonmark,hason/commonmark,postalservice14/commonmark,colinodell/commonmark,garethellis36/commonmark,bcremer/commonmark,thephpleague/commonmark,kkiernan/commonmark,postalservice14/commonmark,hason/commonmark,thephpleague/commonmark,fesor/commonmark