chore: improve setup of the tooling (#4)

* chore: lockfile should be committed to the repo

See https://classic.yarnpkg.com/blog/2016/11/24/lockfiles-for-all/

* chore: explicitly set the npm client to yarn

* chore: set up yarn workspaces

* chore: use jest.config.js

See: https://jestjs.io/docs/en/configuration

Better follow the convention than to define yet another config file name

* test: the `globals` configuration is redundant

* chore: prefer babel.config.js over .babelrc

See https://babeljs.io/docs/en/config-files

* chore: the jsxInjection alias is extraneous

* chore: add .js extension to eslint config

It is the preferred configuration file format.
https://eslint.org/docs/user-guide/configuring#configuration-file-formats

Also deleted the jasmine env as it's not used in this project.

* chore: downgrade to eslint v6 for compatibility with other dependencies

* chore: use eslint-config-airbnb-base instead of the full airbnb config

* chore: remove babel-eslint

Syntax used in this repo can already be parsed with the default ESLint
parser

* chore: add missing peer dependency for `@vue/test-utils`

* chore: enable useWorkspaces in lerna

package.json

@@ -1,4 +1,8 @@
 {
+  "private": true,
+  "workspaces": [
+    "packages/*"
+  ],
   "scripts": {
     "publish": "lerna publish"
   },
@@ -8,9 +12,8 @@
     "jsx"
   ],
   "devDependencies": {
-    "babel-eslint": "^10.1.0",
-    "eslint": "^7.0.0",
-    "eslint-config-airbnb": "^18.1.0",
+    "eslint": "^6.8.0",
+    "eslint-config-airbnb-base": "^14.1.0",
     "eslint-plugin-import": "^2.20.2",
     "lerna": "^3.19.0"
   }