Update dev-dependencies

Author: wooorm

package.json

@@ -35,8 +35,8 @@
     "micromark": "~2.9.0"
   },
   "devDependencies": {
-    "mdast-util-from-markdown": "^0.6.0",
-    "micromark-extension-footnote": "~0.2.0",
+    "mdast-util-from-markdown": "^0.7.0",
+    "micromark-extension-footnote": "~0.3.0",
     "nyc": "^15.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^8.0.0",