Removing tap-xunit dep

Author: evertonfraga

package.json

@@ -92,7 +92,6 @@
     "rlp": "^2.2.3",
     "standard": "^10.0.0",
     "tap-spec": "^5.0.0",
-    "tap-xunit": "2.4.1",
     "tape": "4.6.3",
     "tslint": "^5.16.0",
     "typedoc": "^0.14.2",