chore(npm): use stable

Author: azu

package.json

@@ -39,7 +39,7 @@
     "mocha": "^2.3.3",
     "power-assert": "^1.1.0",
     "sentence-splitter": "^1.0.2",
-    "textlint": "^5.0.0-beta.0",
+    "textlint": "^5.0.0",
     "textlint-tester": "^0.4.0"
   },
   "dependencies": {