Mixpanel tracking for github integration setup

首先，跟踪 issue 中描述的集成设置、GitHub 连接、安装和项目仓库连接流程。为列出的七个事件添加跟踪及其指定属性，包括失败原因，并验证这些事件会在相应的成功和失败流程中触发。

Original comment by @LennonR - https://github.com/code-corps/code-corps-ember/issues/1331#issuecomment-310766129

Mixpanel Tracking Ideas:

1. Loads integrations tab (properties: project_name, project_id)
2. Clicks connect to github button (properties: project_name, project_id)
3. Github connection successful (properties: project_name, project_id)
4. Github connection failed (properties: failure_reason, project_name, project_id)
5. Clicks add project Github integration button (properties: project_name, project_id)
6. Github project integration successful (properties: project_name, project_id)
7. Github project integration failed (properties: failure_reason, project_name, project_id)

Questions:

1. How does the project selection happen when you choose to add a project? Does it take you to github and you choose from your projects? Or is there a UI on code corps that lists projects?

When you go to create an installation, a new tab opens, pointing to the installation url. As you install, you decide between installing on "all the repos for selected user/organization", or only for selected repos.

When you refresh the integration page on code corps, the installation will be listed. You can then "connect it to your code corps organization" and, once that's done, you can connect one or more of the installation-accessible repos to the current project.

2. Is there the option to disconnect/remove a project or a github installation, post connection/installation?

Yes for projects. As it is right now, it simply stops further syncing of new tasks/comments, but keeps the olds ones.

No for installations, at least not from the code corps UI, but it's still possible from github's UI.

3. Once you've connected a project, what has changed about the UI? What can you now do on Code Corps that you couldn't do before?

When you're creating a new task, there will be a dropdown in the sidebar, containing a list of connected repos. If you select a repo from that list, as you create a task, a github issue will also be created in that repo.

From that point on, any edit on the codecorps task will propagate to the github issue and vice versa. The same will happen for comments belonging to that task.