chore: fix #28 umd format without es5 (#29)

Author: evinma

jest.config.js

@@ -2,7 +2,7 @@ module.exports = {
     verbose: false,
     testURL: 'http://localhost',
     collectCoverage: true,
-    collectCoverageFrom: ['src/**'],
+    collectCoverageFrom: ['src/utils.ts'],
     transform: {
         '^.+\\.[j|t]sx?$': 'babel-jest',
     },

package.json

@@ -1,6 +1,6 @@
 {
     "name": "tua-body-scroll-lock",
-    "version": "0.3.0",
+    "version": "0.3.1",
     "description": "🔐Body scroll locking that just works with everything",
     "main": "dist/tua-bsl.umd.js",
     "module": "dist/tua-bsl.esm.js",
@@ -15,7 +15,8 @@
         "start": "rollup -c -w",
         "test": "npm run type-check && cross-env NODE_ENV=test jest",
         "test:tdd": "cross-env NODE_ENV=test jest --watch",
-        "build": "npm run lint && rollup -c && cp index.html dist/index.html",
+        "prebuild": "rimraf dist/* & npm test",
+        "build": "npm run lint && cross-env NODE_ENV=production rollup -c && cp index.html dist/index.html",
         "next": "npm --no-git-tag-version version prerelease",
         "next:m": "npm --no-git-tag-version version preminor",
         "pub": "npm run build && npm publish",