Remove unused dev-dependency

Author: wooorm

package.json

@@ -24,7 +24,6 @@
     "esmangle": "^1.0.1",
     "hastscript": "^3.0.1",
     "nyc": "^11.0.0",
-    "remark": "^8.0.0",
     "remark-cli": "^4.0.0",
     "remark-preset-wooorm": "^3.0.0",
     "tape": "^4.0.0",