chore: update strip-ansi to 6.x (#5)

Author: Trott

package.json

@@ -22,7 +22,7 @@
     "tape": "~4.0.1"
   },
   "dependencies": {
-    "strip-ansi": "~3.0.0",
+    "strip-ansi": "^6.0.1",
     "through2": "~2.0.0"
   }
 }