Upgrade bootstrap alpha to edx-bootstrap (beta)

[thallada]

The includePaths addition to sass-loader is because edx-bootstrap doesn't use webpack, and requires bootstrap sass like this:

@import 'bootstrap/scss/functions';

Instead of:

@import '~bootstrap/scss/functions';

(I'll add a note about this to their README.)

The rest is addressing all of the variable changes/removals between bootstrap alpha6 and beta.

@arizzitano I have no idea what the paragon-reset looks like now so you might want to test to see if it still looks right wherever it's being used. I just did my best to get it to compile.

[coveralls]

Coverage remained the same at 98.396% when pulling 8c5b279 on thallada/edx-bootstrap into 0b291c8 on master.

[thallada]

I hope that this won't break theming in clients of paragon since all of the variables in the theme are defined with !default. Without this here the scss won't compile.

[efischer19]

😬

Seems like an issue all right. How can we test that/how can we remove that dependency?

[arizzitano]

!default is kind of the opposite of !important. Any variable definition in the same scope without !default will override the default -- even if that variable is defined before the default. So as long as themes define these vars without !default, we should be fine.

[thallada]

Because we had concerns about this, I tested it out to make sure. Say we have a theme:

// ./src/_theme.scss
$red: #d9534f;
$brand-primary: $red;

As long as we import it before @import "paragon-reset";, then that theme will override anything in the openedx theme. The webpack config in our project for doing that:

{
  loader: 'sass-loader',
    options: {
      sourceMap: true,
      data: '@import "red-theme"; @import "paragon-reset";',
      includePaths: [
        path.join(__dirname, '../src'),
        path.join(__dirname, '../node_modules/paragon/src/utils'),
        path.join(__dirname, '../node_modules'),
      ],
   },
},

[efischer19]

Everything seems logical to me; that theming issue might be a bear though. Let's try to get that straightened out.

[efischer19]

😬

Seems like an issue all right. How can we test that/how can we remove that dependency?

[efischer19]

(I don't feel like my review should block merging though - if you and @arizzitano come to a consensus, run with it)

[arizzitano]

👍 thanks for this @thallada!

[arizzitano]

!default is kind of the opposite of !important. Any variable definition in the same scope without !default will override the default -- even if that variable is defined before the default. So as long as themes define these vars without !default, we should be fine.

[arizzitano]

Just noticed some issues with the dropdown styling -- I can either fix them in this PR or do a followon PR, whatever's easier for you.