bump devDependencies

Author: BarryThePenguin

package.json

@@ -42,15 +42,15 @@
     "browserify": "^13.0.1",
     "esmangle": "^1.0.1",
     "istanbul": "^0.4.4",
-    "remark": "^5.0.1",
-    "remark-cli": "^1.0.0",
+    "remark": "^6.2.0",
+    "remark-cli": "^2.1.0",
     "remark-comment-config": "^4.0.1",
-    "remark-github": "^5.1.0",
-    "remark-lint": "^4.0.2",
-    "remark-parse": "^1.0.0",
-    "remark-stringify": "^1.0.0",
+    "remark-github": "^6.0.0",
+    "remark-lint": "^5.4.0",
+    "remark-parse": "^2.2.0",
+    "remark-stringify": "^2.3.0",
     "remark-usage": "^4.0.0",
-    "remark-validate-links": "^4.0.0",
+    "remark-validate-links": "^5.0.0",
     "tape": "^4.6.0",
     "xo": "^0.16.0"
   },