up symfony version to 2.6
change symfony version in travis
standardization code
Merge remote-tracking branch 'upstream/master' into up_symfony_to_2_6_version
code stardartization
Merge pull request #64 from tfe2012/up_symfony_to_2_6_version

up symfony version to 2.6
Merge remote-tracking branch 'upstream/master'

Conflicts:
	EventListener/AbstractImportConsumeEventListener.php
	EventListener/ImportSourceEventListener.php
	Import/DoctrineImportIterator.php
	Pipeline/Item/AbstractImportItem.php
	Pipeline/Item/SyncExecuteItem.php