revert removal of prepublish, update rollup resolve plugin config syntax

Author: AlexanderRichey

.travis.yml

@@ -6,5 +6,4 @@ before_install:
   - npm i -g codecov
 script:
   - yarn test
-  - yarn build
   - codecov

package.json

@@ -7,6 +7,7 @@
   "scripts": {
     "test": "jest --coverage --verbose",
     "lint": "prettier src/ tests/",
+    "prepublish": "yarn run build",
     "build": "rollup -c rollup.config.js"
   },
   "repository": {

rollup.config.js

@@ -28,9 +28,7 @@ export default {
   plugins: [
     resolve({
       extensions: [".jsx", ".js"],
-      customResolveOptions: {
-        moduleDirectories: ["node_modules"]
-      }
+      moduleDirectories: ["node_modules"]
     }),
     replace({
       "process.env.NODE_ENV": JSON.stringify("production"),