[Button] Make the outlined variant better leverage the color

[essuraj]

• Changed the color of the outline of the button when the button color is primary and secondary based on the theme used.
• Changed the outline width to 2px from 1px as it is what the official material docs use, plus they look good.

[oliviertassinari]

Changed the color of the outline of the button when the button color is primary and secondary based on the theme used.

I have no objection to this change. It's what vuetify and angular material are doing. It's also creating more override flexibility with the two new class keys 👍 .

Changed the outline width to 2px from 1px as it is what the official material docs use, plus they look good.

MCW is the only one to do this, it even goes against the official specification. I don't think that we should be following them.

@mbrookes What do you think?

[mbrookes]

I agree with @oliviertassinari about not changing the border-width.

Regarding the border color, perhaps it might be better if only applied when focused, in order to stay closer to the spec?

Alternatively, perhaps it could take the primary /secondary color, but with reduced opacity when not hovered or focused?

[essuraj]

changed back to 1px width and added color opacity on hover

[mbrookes]

border needs to be added to the transition, and you'll need to update the docs with yarn docs:api, fix the failing test, and ideally add tests for these styles.

What should the style be when focused?

[essuraj]

right now it looks like so, this is my first pull request, i dont understand where i must change so that the tests pass. Running yarn docs:api is building all md files and shows i must commit 200 files..

i'm getting this

1608 passing (5s)
1 failing

1. server side should be able to extract the styles:

   AssertionError: expected 'MuiTouchRipple-root-30' to equal 'MuiTouchRipple-root-28'

   • expected - actual

   -MuiTouchRipple-root-30
   +MuiTouchRipple-root-28

   at Context. (packages\material-ui\src\styles\MuiThemeProvider.test.js:103:20)

[oliviertassinari]

@mbrookes The pull request should be green now. I haven't changed the direction @essuraj took. Have a final look at it :).

[mbrookes]

@essuraj Thanks for contributing!