Move babel-plugin-preval to dependencies (#4209)

package.json

@@ -25,6 +25,7 @@
     "babel-core": "^6.25.0",
     "babel-loader": "^7.1.1",
     "babel-plugin-lodash": "^3.2.11",
+    "babel-plugin-preval": "^1.3.2",
     "babel-plugin-react-intl": "^2.3.1",
     "babel-plugin-react-transform": "^2.0.2",
     "babel-plugin-syntax-dynamic-import": "^6.18.0",
@@ -121,7 +122,6 @@
     "@storybook/addon-actions": "^3.1.8",
     "@storybook/react": "^3.1.8",
     "babel-eslint": "^7.2.3",
-    "babel-plugin-preval": "^1.3.2",
     "chai": "^4.1.0",
     "chai-enzyme": "^0.8.0",
     "enzyme": "^2.9.1",