chore(npm): update alex@3

Author: azu

package.json

@@ -33,14 +33,14 @@
   ],
   "devDependencies": {
     "babel-cli": "^6.5.1",
-    "babel-plugin-add-module-exports": "^0.1.2",
+    "babel-plugin-add-module-exports": "^0.2.1",
     "babel-preset-es2015": "^6.5.0",
     "babel-register": "^6.5.2",
     "mocha": "^2.4.5",
-    "textlint-tester": "^0.4.1"
+    "textlint-tester": "^2.0.0"
   },
   "dependencies": {
-    "alex": "^2.0.1",
-    "textlint-rule-helper": "^1.1.5"
+    "alex": "^3.1.0",
+    "textlint-rule-helper": "^2.0.0"
   }
 }