diff -u b/core/package.json b/core/package.json
--- b/core/package.json
+++ b/core/package.json
@@ -9,7 +9,7 @@
     "build:js-dev": "cross-env NODE_ENV=development node ./scripts/js/babel-es6-build.js",
     "watch:js": "node ./scripts/js/babel-es6-watch.js",
     "watch:js-dev": "cross-env NODE_ENV=development node ./scripts/js/babel-es6-watch.js",
-    "lint:core-js": "eslint --ext=.es6.js . || exit 0",
+    "lint:core-js": "node ./node_modules/eslint/bin/eslint.js --ext=.es6.js . || exit 0",
     "lint:css": "stylelint \"**/*.css\" || exit 0",
     "lint:css-checkstyle": "stylelint \"**/*.css\" --custom-formatter ./node_modules/stylelint-checkstyle-formatter/index.js || exit 0"
   },
@@ -24,11 +24,11 @@
     "eslint-plugin-import": "2.2.0",
     "eslint-plugin-jsx-a11y": "4.0.0",
     "eslint-plugin-react": "6.10.3",
-    "exec-then": "^1.3.1",
-    "fs-extra": "^3.0.1",
+    "exec-then": "1.3.1",
+    "fs-extra": "3.0.1",
     "glob": "7.1.1",
-    "node-fetch": "^1.6.3",
-    "parse-diff": "^0.4.0",
+    "node-fetch": "1.6.3",
+    "parse-diff": "0.4.0",
     "stylelint": "^7.10.1",
     "stylelint-checkstyle-formatter": "^0.1.0",
     "stylelint-config-standard": "^16.0.0",
diff -u b/core/yarn.lock b/core/yarn.lock
--- b/core/yarn.lock
+++ b/core/yarn.lock
@@ -1260,7 +1260,7 @@
     d "1"
     es5-ext "~0.10.14"
 
-exec-then@^1.3.1:
+exec-then@1.3.1:
   version "1.3.1"
   resolved "https://registry.yarnpkg.com/exec-then/-/exec-then-1.3.1.tgz#a7a87bf0a008ad6e03a7550f1a1c601fe697c0bb"
   dependencies:
@@ -1380,7 +1380,7 @@
     combined-stream "^1.0.5"
     mime-types "^2.1.12"
 
-fs-extra@^3.0.1:
+fs-extra@3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-3.0.1.tgz#3794f378c58b342ea7dbbb23095109c4b3b62291"
   dependencies:
@@ -2100,7 +2100,7 @@
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/natural-compare/-/natural-compare-1.4.0.tgz#4abebfeed7541f2c27acfb29bdbbd15c8d5ba4f7"
 
-node-fetch@^1.6.3:
+node-fetch@1.6.3:
   version "1.6.3"
   resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-1.6.3.tgz#dc234edd6489982d58e8f0db4f695029abcd8c04"
   dependencies:
@@ -2241,7 +2241,7 @@
     os-homedir "^1.0.0"
     os-tmpdir "^1.0.0"
 
-parse-diff@^0.4.0:
+parse-diff@0.4.0:
   version "0.4.0"
   resolved "https://registry.yarnpkg.com/parse-diff/-/parse-diff-0.4.0.tgz#9ce35bcce8fc0b7c58f46d71113394fc0b4982dd"