(chore) Update dependencies

- Update to latest major versions: `babel`, `jest`, `redux-saga`, `reselect` and `styled-components`
- Replace `babel-polyfill` with `core-js`
- Drop Node.js 8 support
- Disable styled components snapshot tests: `styled-components@4` doesn't support snapshot yet
- Update snapshots after updating React
- Don't support Node.js 12 yet due to `natives` module incompatibility (nodejs/node#27422)

.babelrc

@@ -1,15 +1,15 @@
 {
   "plugins": [
     [ "styled-components", { "displayName": false, "ssr": true }],
-    "transform-class-properties",
-    "transform-object-rest-spread",
-    "syntax-dynamic-import",
+    "@babel/plugin-proposal-class-properties",
+    "@babel/plugin-proposal-object-rest-spread",
+    "@babel/plugin-syntax-dynamic-import",
     "react-loadable/babel"
   ],
   "presets": [
-    ["env", { "modules": false }],
-    "flow",
-    "react"
+    ["@babel/preset-env", { "modules": false }],
+    "@babel/preset-flow",
+    "@babel/preset-react"
   ],
   "retainLines": true,
   "env": {
@@ -22,10 +22,10 @@
     "test": {
       "plugins": [
         [ "styled-components", { "fileName": false }],
-        "transform-class-properties",
+        "@babel/plugin-proposal-class-properties",
         "dynamic-import-node"
       ],
-      "presets": ["env", "react"]
+      "presets": ["@babel/preset-env", "@babel/preset-react"]
     }
   }
 }

.travis.yml

@@ -1,7 +1,6 @@
 language: node_js
 
 node_js:
-  - "8"
   - "10"
 
 cache:

jest.config.js

@@ -17,5 +17,5 @@ module.exports = {
   ],
   coverageReporters: ['lcov', 'text'],
   transformIgnorePatterns: ['node_modules/(?!(lodash-es)/)'],
-  setupTestFrameworkScriptFile: '<rootDir>jest/setup.js'
+  setupFilesAfterEnv: ['<rootDir>jest/setup.js']
 }

jest/setup.js

@@ -1,11 +1,8 @@
-import promiseFinally from 'promise.prototype.finally'
+import 'regenerator-runtime/runtime'
 
 import Enzyme, { shallow, render, mount } from 'enzyme'
 import Adapter from 'enzyme-adapter-react-16'
 
-// Bring '.finally' to Promise (only for Node 8). Will be available in Node 10
-promiseFinally.shim()
-
 Enzyme.configure({ adapter: new Adapter() })
 
 // Make Enzyme functions available in all test files without importing

jest/test-helpers.jsx

@@ -86,7 +86,7 @@ export const runSaga = (saga, state = {}, arg1 = undefined) => {
     },
     saga,
     arg1
-  ).done.then(() => {
-    return dispatched
-  })
+  )
+    .toPromise()
+    .then(() => dispatched)
 }