Update babylon to 7.0-beta.4 (#165)

Author: danez

package.json

@@ -30,7 +30,7 @@
   "dependencies": {
     "async": "^2.1.4",
     "babel-runtime": "^6.9.2",
-    "babylon": "7.0.0-beta.3",
+    "babylon": "7.0.0-beta.4",
     "commander": "^2.9.0",
     "doctrine": "^2.0.0",
     "node-dir": "^0.1.10",

yarn.lock

@@ -731,9 +731,9 @@ babel-types@^6.15.0, babel-types@^6.18.0, babel-types@^6.19.0, babel-types@^6.22
     lodash "^4.2.0"
     to-fast-properties "^1.0.1"
 
-[email protected].3:
-  version "7.0.0-beta.3"
-  resolved "https://registry.yarnpkg.com/babylon/-/babylon-7.0.0-beta.3.tgz#d2204f157a88000bc1645d5c1c89c392f664ab7b"
+[email protected].4:
+  version "7.0.0-beta.4"
+  resolved "https://registry.yarnpkg.com/babylon/-/babylon-7.0.0-beta.4.tgz#82db799d2667f61bbaf34456dbfa91c37613459d"
 
 babylon@^6.11.0, babylon@^6.13.0, babylon@^6.15.0:
   version "6.16.1"