Update Bootstrap version

[chocoelho]

Description

This PR updates supported Bootstrap 4 version from alpha to beta. normalize was removed from beta version, so we don't need that in .bootstraprc anymore.

Motivation and Context

Resolves #125. We upgrade from alpha to beta version of Bootstrap 4.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires documentation updates.
• I have updated the documentation accordingly.
• My change requires dependencies updates.
• I have updated the dependencies accordingly.

[aericson]

Hey @chocoelho

Did you check the changes in shakacode/bootstrap-loader#316 ?

I only did a quick look but a few changes that might require researching into why they made them:

• Removed responsive-embed: true from .bootstraprc-4-default
• Removed useFlexbox: true and all mentions/documentation of it. We use useFlexbox: false. Does that still work? I think this won't work because of this change. If so, how can we disable it and do we still have a valid reason to disable it? Maybe @laisvarejao can help.
• They changed the order of sass-loader and postcss-loader in their example. They might have had a good reason to do it.

If you have taken those into consideration and they don't require any further changes disconsider it.

[chocoelho]

Thanks, @aericson. I also noticed that I had forgotten to include Popper.js configuration in webpack.

As to what you said:

Removed responsive-embed: true from .bootstraprc-4-default

• I just removed that, even though it was set to false, but that's not working anymore

Removed useFlexbox: true and all mentions/documentation of it. We use useFlexbox: false. Does that still work? I think this won't work because of this change. If so, how can we disable it and do we still have a valid reason to disable it? Maybe @laisvarejao can help.

• They removed useFlexbox option since BS4 uses flexboxes by default. I don't know if that's something we can change right now.

They changed the order of sass-loader and postcss-loader in their example. They might have had a good reason to do it.

• Basically, because order matters. Thanks for noticing that, I fixed it.

[laisvarejao]

@aericson where did you see that the order of the sass-loader and postcss-loader changed?
I don't see this in the example:
https://github.com/shakacode/bootstrap-loader/blob/master/.bootstraprc-4-default

@aericson @chocoelho yes, Flexbox is now the only option! This has changed since Alpha 6:

Flexbox is now on by default, with no fallback! This means we've dropped IE9 support, but with significant savings to our code base, simpler components, and improved customization thanks to the power of flexbox. (twbs/bootstrap#20939)

• I've also noticed they are alphabetically ordering the styles components in bootstrap.rc. I think this is a good standard to follow.

[chocoelho]

@laisvarejao about the changed order: shakacode/bootstrap-loader#316 (comment)

[chocoelho]

Regarding the alphabetic order, that can be done as well and I agree with it.