- Fix test cases not running for desktop OS detection.
- Fixes application throwing error when user agent is undefined.
- Refactor by making os property optional in Environment to explicit
describe its potential undefined state.
Alias would remove unnecessary repetitions and less relative paths make changes easier when moving around files. This commit cleans also up some relative paths ('../../../') by using the alias and orders imports. It updates both path alias in tsconfig and module alias in Vue CLI's bundler (vuejs/vue-cli#2398).
