Add the ability for crate authors to add isitmaintained.com badges to their crate

[carols10cents]

Part of RFC 1824, rust-lang/rust#41616.

isitmaintained.com provides badges indicating the time to resolution of GitHub issues and percentage of GitHub issues that are open.

We will enable maintainers to add these badges to their crate, in a similar way that the TravisCI/Appveyor/Gitlab badges are implemented today.

Also need to update the documentation that currently lives in cargo's repo.

Please let me know if you have any questions, potential implementers!

[nisargthakkar]

Hey @carols10cents, I'd like to pick up this task

[carols10cents]

Awesome!! I'm imagining that this would fit in to the existing system of CI badges-- take a look in these spots:

• The Badge enum will need a new variant:

  crates.io/src/badge.rs

  Line 15 in b41061f

  pub enum Badge {

• The badge_type match will need a new arm:

  crates.io/src/badge.rs

  Line 62 in b41061f

  pub fn badge_type(&self) -> &'static str {

• Add to the tests in https://github.com/rust-lang/crates.io/blob/master/src/tests/badge.rs
• Add a component in https://github.com/rust-lang/crates.io/tree/master/app/components
• Add a template in https://github.com/rust-lang/crates.io/tree/master/app/templates/components
• Add an instance of the new badge in this front-end test fixture

  crates.io/mirage/fixtures/search.js

  Line 23 in b41061f

  "badges": [

• Add a front-end test looking for the HTML (it doesn't have to actually load the badge, just generate the correct HTML) here:

  crates.io/tests/acceptance/search-test.js

  Line 27 in b41061f

  findWithAssert('#crates .row:first .desc .info .badge:first a[href="https://ci.appveyor.com/project/huonw/external_mixin"]');

• And then finally make another PR to add documentation over in cargo's repo here: https://github.com/rust-lang/cargo/blob/master/src/doc/manifest.md#package-metadata

Please let me know if you have any questions at all!!!

[nisargthakkar]

@carols10cents I was able to set up the badges correctly for isitmaintained (issue resolution and open issues), codecov and coveralls.
I'm not sure what to set the content when the mouse is hovered on it.

This is what I have set currently:
Is It Maintained average time to resolve an issue
Is It Maintained percentage of issues still open
CodeCov coverage status for the branch
Coveralls coverage status for the branch

The ones for isitmaintained do not feel right, though. It would be great if you could suggest some improvements

[carols10cents]

They sound fine to me, what doesn't feel right about them?

[nisargthakkar]

I think it would be better if there were some punctuations like
Is It Maintained: Average time to resolve an issue

Also in the previous comment, i messed up in markdown, the text for CodeCov and Coveralls was set to:
CodeCov coverage status for the <branch> branch
Coveralls coverage status for the <branch> branch

[carols10cents]

Fixed by #726!! Thank you @nisargthakkar!!!