added zend studio to gitignore

.gitignore

-/.idea/
-/nbproject/
+# phpstorm project files
+.idea
+
+# netbeans project files
+nbproject
+
+# zend studio for eclipse project files
+.buildpath
+.project
+.settings
+
+# windows thumbnail cache
 Thumbs.db
\ No newline at end of file