Cleanup gitignore file (#4183)

.gitignore

@@ -1,13 +1,9 @@
-build
-phpunit.xml
-Resources/doc/_build/*
-nbproject
-.idea
-coverage
-composer.lock
+/build
 /vendor
-composer.phar
+/Resources/doc/_build/*
 .php_cs.cache
+composer.lock
+phpunit.xml
 
 # clean up some non bower ready package
 Resources/public/vendor/admin-lte/bootstrap