Rewrite calendar filters with React components

.babelrc.js

@@ -0,0 +1,9 @@
+module.exports = {
+  presets: [
+    "@babel/preset-env"
+  ],
+  plugins: [
+    '@wordpress/babel-plugin-import-jsx-pragma',
+    '@babel/plugin-transform-react-jsx',
+  ]
+}

.prettierrc.js

@@ -0,0 +1,3 @@
+// Import the default config file and expose it in the project root.
+// Useful for editor integrations.
+module.exports = require('@wordpress/prettier-config');

.travis.yml

@@ -98,4 +98,5 @@ script:
       $( npm bin )/wp-scripts test-e2e --config=./tests/e2e/jest.config.js
       bash bin/phpcs-diff.sh
       npm run lint
+      npm run test-jest
     fi

jest.config.js

@@ -0,0 +1,7 @@
+module.exports = {
+    testMatch: ["<rootDir>/tests/jest/**/**.test.js"], // finds test
+    moduleNameMapper: {
+        "^.+\\.(css|less|scss)$": "babel-jest"
+    },
+    preset: '@wordpress/jest-preset-default',
+};