feat: please introduce a better testing strategy

[tafelnl]

First of all, thanks for your work on this essential plugin for Vue.

I have an important 'feature' request, which I think is necessary to be able to release a stable version of this plugin. And it's about implementing a solid testing strategy.

Everytime a new release is published, a bunch of regression or new bugs show up. This is the ultimate sign of a bad testing strategy. And it's true, because most PRs (both features and bug fixes) get merged without an accompanying test.

A few examples of issues, that probably could have been prevented with proper testing:

• https://github.com/vuejs/apollo/issues/1315
• https://github.com/vuejs/apollo/issues/1397
• https://github.com/vuejs/apollo/issues/1432
• https://github.com/vuejs/apollo/issues/1462
• https://github.com/vuejs/apollo/issues/936
• https://github.com/vuejs/apollo/issues/847
• https://github.com/vuejs/apollo/issues/1297
• https://github.com/vuejs/apollo/issues/1336

and probably some more.

A few examples of recently merged PRs without an accompanying test:

• https://github.com/vuejs/apollo/pull/1425
• https://github.com/vuejs/apollo/pull/1388

[websitevirtuoso]

I think the owner of the lib will always get help, like new tests, bug fixes, improvements, and any related help.