fix version check error, when xcode upgrade to 10.0 (#447)

Author: mingz2013

plugins/plugin_compile/project_compile.py

@@ -545,7 +545,7 @@ def build_android(self):
     def check_ios_mac_build_depends(self):
         version = cocos.get_xcode_version()
 
-        if version <= '5':
+        if cocos.version_compare(version, "<=", 5):
             message = MultiLanguage.get_string('COMPILE_ERROR_UPDATE_XCODE')
             raise cocos.CCPluginError(message, cocos.CCPluginError.ERROR_TOOLS_NOT_FOUND)