The main things I'm seeing right now are:
1. Some selectors are broken up into multiple selectors, especially when
there are pseudo classes involved where the output is unknown. For
example `::ng-deep, ::v-deep {}` will be split into `::ng-deep {},
::v-deep {}`
2. It looks like a lot of selectors were dropped, however after looking
at them in more detail I noticed that they were _duplicated_ before.
This means that now the output will be smaller in these cases!
* move `preflight` tests to `plugins` test folder
* move `container` tests to `plugins` test folder
* add a test that ensures that all built-in plugins have tests
This is based on a few assumptions:
1. All plugins exist in the `corePlugins.js` file and are exported as
`corePlugins`
2. Each exported plugin in that object has a file with a corresponding
name in the current (`tests/plugins/`) folder
* add dedicated plugin tests in the `plugins` folder
* add a test that ensures that all built-in variant plugins have tests
This is based on a few assumptions:
1. All variant plugins exist in the `corePlugins.js` file and are
exported as `variantPlugins`
2. Each exported plugin in that object has a file with a corresponding
name in the current (`tests/plugins/variants/`) folder
* add dedicated variant plugin tests in the `plugins/variants` folder
* cleanup basic usage test
* move existing animation tests to animation plugin tests
* move `apply-important-selector` tests to more appropriate location
