Feature/86 cleaner style for Ecosystem tabs widget

[joelachance]

This would eventually resolve #86.

The current tab layout doesn't look good for mobile, and has some additional shortcomings.
In this PR, I've added UI Kit tabs, moved each tabs' content into its own partial, and updated some of the styling.

This still to be done here:

• Update content for mobile. This would be for 'Visualization', 'Data Science', 'Machine Learning'. Move images to showcase them a bit more!
• Add carousel for 'Scientific Domains' and 'Array Libraries' tabs (i.e. slideshow through the logos and links, vs. rendering all at once)

I'm hoping to get feedback on what's been done so far before moving forward.

Last thing to note: I think the content in the homepage isn't dispersed very equally. Our 'in a nutshell' section is much simpler than our tabs, and feels a bit light in comparison. I'd like to suggest we try to compress what we have for the tabs so it's a little easier for people just visiting the site for the first time to glance over, or perhaps distribute to another section? It would be great to hear what others think! (I hope no offense taken here, I know a lot of effort has gone into tab content to date!)

[rgommers]

Thanks Joe! A few thoughts:

• Tab styling is very clean, I like it
• The title and text alignment is off, no margins - but I'm sure you knew that already. I'm guessing a 15% margin left and right would look about right.
• I think the content can indeed be reduced a little, in particular limit to a single image per tab (visualization and data science have two now). let's do that in a separate PR though. I also still need to edit the text.
• Specifically for the "array libraries" tab, we can move the overview of libraries to the "array computing" tab (we considered that before), and then have larger logos/text on that separate page. Then no need to have a carousel there; carousels are nice for unrelated items, but here it's good to have a single overview

[joelachance]

I made a fix to the content width for all tabs. The title should be identical to 'Key Features' now, but if not I can fix those soon.

Everything else looks like a content change-- I created a ticket specifically for those here: #158

If everything else looks good, let's merge!

[shaloo]

Joel, I'll take a look at this today and share additional inputs.

The new tabs look much better. As per @rgommers comments I will try to re-fix the content via separate PR (issue #158) as suggested for bullets 3 and 4.

• I think the content can indeed be reduced a little, in particular limit to a single image per tab (visualization and data science have two now). let's do that in a separate PR though. I also still need to edit the text.
• Specifically for the "array libraries" tab, we can move the overview of libraries to the "array computing" tab (we considered that before), and then have larger logos/text on that separate page. Then no need to have a carousel there; carousels are nice for unrelated items, but here it's good to have a single overview

[shaloo]

@joelachance - Will you be taking care of bullet #2 regarding tab title alignment with the text in the tab below?

[joelachance]

@shaloo I'll take care of #2! It's on my list.

[joelachance]

Fixed some padding, let me know what everyone thinks.

[rgommers]

LGTM now, only had to fix a small merge conflict - in it goes!

[rgommers]

Or, maybe I should review more carefully before hitting the green button on a rebase - this just broke the styling of the "Key features" tiles.

[rgommers]

Fixed in commit 0a66c22, lost one CSS include in the rebase