New-GitLabBuild sets uri to specific gitlab instance (columbia.csc)

[aldrichtr]

1. Provide a general summary of the issue in the Title above

2. Describe Your Environment

Operating System and PowerShell version: Windows 10 20H2 / 7.1.3

3. Expected Behavior

New-GitLabBuild creates new build on a Gitlab server of the user's choosing

4.Current Behavior

New-GitLabBuild generates an API call to gitlab.columbia.csc
PSGitLab/Public/Build/New-GitLabBuild.ps1 line # 22

5. Possible Solution

Provide a Uri parameter to the New-GitLabBuild function and/or use the $Domain Configuration setting
I intend to provide a PR for this issue

6. Context

use the New-GitLabBuild to trigger a build in my environment.