fix(package): update eventemitter3 to version 4.0.4

Closes #12

Author: greenkeeper[bot]

package.json

@@ -42,7 +42,7 @@
   "dependencies": {
     "diagnostics": "~1.1.0",
     "dollars": "0.0.x",
-    "eventemitter3": "~3.0.0",
+    "eventemitter3": "~4.0.4",
     "fusing": "1.0.x",
     "juice2": "1.3.x",
     "marked": ">= 0.3.3",