Upgrade test reporter

taper v0.4.0 has a workaround for tapjs/tapjs#109 and
tape-testing/tape#140, a bug I was experiencing in writing some new tests.

package.json

@@ -58,6 +58,6 @@
     "karma-tap": "~1.0.1",
     "rimraf": "~2.2.8",
     "tape": "~3.0.0",
-    "taper": "~0.3.0"
+    "taper": "~0.4.0"
   }
 }