Move node-sass to devDependencies

package.json

@@ -98,7 +98,6 @@
     "jshashes": "^1.0.7",
     "keytar": "^4.0.3",
     "localforage": "^1.5.0",
-    "node-sass": "^4.7.2",
     "npm": "^5.5.1",
     "rc-progress": "^2.0.6",
     "react": "^15.4.0",
@@ -146,6 +145,7 @@
     "json-loader": "^0.5.4",
     "lint-staged": "^3.6.0",
     "node-loader": "^0.6.0",
+    "node-sass": "^4.7.2",
     "prettier": "^1.4.2",
     "sass-loader": "^6.0.6",
     "style-loader": "^0.19.0",

yarn.lock

@@ -4578,7 +4578,11 @@ jayson@^2.0.2:
     json-stringify-safe "5.0.1"
     lodash "3.6.0"
 
-js-base64@^2.1.8, js-base64@^2.1.9:
+js-base64@^2.1.8:
+  version "2.4.0"
+  resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.4.0.tgz#9e566fee624751a1d720c966cd6226d29d4025aa"
+
+js-base64@^2.1.9:
   version "2.3.2"
   resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.3.2.tgz#a79a923666372b580f8e27f51845c6f7e8fbfbaf"