chore(package): update postcss to version 7.0.1 (#88)

Closes #85

Author: gucong3000

package.json

@@ -26,7 +26,7 @@
     "eslint-plugin-standard": "^3.1.0",
     "mocha": "^5.2.0",
     "nyc": "^12.0.2",
-    "postcss": "^7.0.0",
+    "postcss": "^7.0.1",
     "postcss-less": "^2.0.0",
     "postcss-reporter": "^5.0.0",
     "stylelint": "^9.3.0"