build(travis): try without acorn pkg

Author: mydearxym

package.docker.json

@@ -16,7 +16,6 @@
     "@zeit/next-css": "^1.0.1",
     "@zeit/next-source-maps": "0.0.4-canary.1",
     "accepts": "^1.3.4",
-    "acorn": "^6.1.1",
     "antd": "3.8.4",
     "apollo-cache-inmemory": "1.6.2",
     "apollo-client": "2.6.3",

package.json

@@ -47,7 +47,6 @@
     "@zeit/next-css": "^1.0.1",
     "@zeit/next-source-maps": "0.0.4-canary.1",
     "accepts": "^1.3.4",
-    "acorn": "^6.1.1",
     "antd": "3.8.4",
     "apollo-cache-inmemory": "1.6.2",
     "apollo-client": "2.6.3",

yarn.lock

@@ -1544,7 +1544,7 @@ acorn@^5.5.3:
   version "5.7.3"
   resolved "https://registry.npmjs.org/acorn/-/acorn-5.7.3.tgz#67aa231bf8812974b85235a96771eb6bd07ea279"
 
-acorn@^6.0.1, acorn@^6.0.5, acorn@^6.0.7, acorn@^6.1.1:
+acorn@^6.0.1, acorn@^6.0.5, acorn@^6.0.7:
   version "6.1.1"
   resolved "https://registry.npmjs.org/acorn/-/acorn-6.1.1.tgz#7d25ae05bb8ad1f9b699108e1094ecd7884adc1f"