Added readable_directory
Added class_exists check
Added stream_wrapper_exists check
Added cpu_performance check
require symfony 2.3+, added composer suggests
tightened up configuration (closes #51)
Merge pull request #58 from frne/full_zend_diagnostics_check_integration

Full integration of existing ZendDiagnostics checks
fix typo
added some tests
change dev-master to 2.5.*@dev in travis config
add --prefer-source flag
use full symfony for travis tests
enforce coding standards
fix typo
fix cs
add build status image to readme
remove dep_entires check (closes #59)
added custom_error_pages test (closes #60)
added scrutinizer badge
made some fixes based on scrutinizer recommendations