Fixed acorn versions range

package.json

@@ -23,7 +23,7 @@
   "dependencies": {
     "@gradecam/tsenum": "1.2.0",
     "@nuxtjs/opencollective": "0.2.2",
-    "acorn": "^7.1.0",
+    "acorn": "7.1.0",
     "chalk": "3.0.0",
     "chance": "1.1.4",
     "class-validator": "0.11.0",

yarn.lock

@@ -452,16 +452,16 @@ abbrev@1:
   resolved "https://registry.yarnpkg.com/abbrev/-/abbrev-1.1.1.tgz#f8f2c887ad10bf67f634f005b6987fed3179aac8"
   integrity sha512-nne9/IiQ/hzIhY6pdDnbBtz7DjPTKrY00P/zvPSm5pOFkl6xuGrGnXn/VtTNNfNtAfZ9/1RtehkszU9qcTii0Q==
 
[email protected]:
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-7.1.0.tgz#949d36f2c292535da602283586c2477c57eb2d6c"
+  integrity sha512-kL5CuoXA/dgxlBbVrflsflzQ3PAas7RYZB52NOm/6839iVYJgKMJ3cQJD+t2i5+qFa8h3MDpEOJiS64E8JLnSQ==
+
 acorn@^6.2.1:
   version "6.4.0"
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-6.4.0.tgz#b659d2ffbafa24baf5db1cdbb2c94a983ecd2784"
   integrity sha512-gac8OEcQ2Li1dxIEWGZzsp2BitJxwkwcOm0zHAJLcPJaVvm58FRnk6RkuLRpU1EujipU2ZFODv2P9DLMfnV8mw==
 
-acorn@^7.1.0:
-  version "7.1.0"
-  resolved "https://registry.yarnpkg.com/acorn/-/acorn-7.1.0.tgz#949d36f2c292535da602283586c2477c57eb2d6c"
-  integrity sha512-kL5CuoXA/dgxlBbVrflsflzQ3PAas7RYZB52NOm/6839iVYJgKMJ3cQJD+t2i5+qFa8h3MDpEOJiS64E8JLnSQ==
-
 aggregate-error@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/aggregate-error/-/aggregate-error-3.0.1.tgz#db2fe7246e536f40d9b5442a39e117d7dd6a24e0"