Gitbucket color scheme

[Neiko2002]

The design of the arrow icon in the explorer view is a little bit off. This PR adds the Gitbucket color scheme to the icon and removes the outlines when it is focused.

[tomoki1207]

@Neiko2002 Thank you contributing.
Is "little bit off" means that the vertical alignment of the button beside the Files tab and the badges beside the other tabs is different?
It looks not fixed by this PR.

About color scheme, the appearance should be differ between the button and other badges for clearly to be able to click or not, imho.
But the gray color might not be nice as you felt. ;)

[Neiko2002]

You are right the alignment is also a little bit of. But I was only referring to the color scheme. If we want to make it distinguishable from the other badges, we could use the design of the "+" button in the "files overview".

Adding "btn btn-default" to the class of the button element above is sufficient.

[tomoki1207]

Thank you quickly fix!
I also tried adjusting alignments based on your styles then I wrote it each comments.
Please could you review it?

[tomoki1207]

The icon content alignment when expanded is little bit off by these style.
And I think the button and badges should be aligned by center rather than right.
The below styles looks good for me.

  padding: 0;
  width: 25px;
  height: 25px;
  right: 10px;

[tomoki1207]

Only width: 10px; is enough in this block for apply the style of btn-default and centering the icon contents.

[Neiko2002]

I like your suggestions. The btn-default class would give the button a hover effect. We might want to add the effect if we don't want to use the class.

[tomoki1207]

I think it is better to use btn-default because it style provides us unified design.
Well, could you modify the files with our conversations and then rebase these commits?

[Neiko2002]

I've tried a smaller version of the expander button, having the same size as the other badges. I like this version the best. What do you think?

[tomoki1207]

Sorry for late reply.
The smaller version is nice but I think the normal version is better.
Because the look of normal version is similar to octotree and familiar its users.

[Neiko2002]

I have taken a look at the octotree design and changed my commit to resample it. How do you like it?

[tomoki1207]

It looks nice. Thank you for work!