How can my manager/colleague execute these scripts in his or her machine?
I see two approaches:
- They can check-out project (clone repository in Git nomenclature) to their local machine
- You may create a build/zip with your test scripts and share it via Nexus, Artifactory or any other artifacts repository you use for sharing components/libraries.
However, it may be time-consuming for them to download and setup necessary environment on their machines.
If you want your colleagues to see test results you may consider using any continuous integration (CI) server, e.g., Jenkins, Hudson, TeamCity. Each of them takes test scripts from Version Control System (GitHub in your case) and execute them on designated machines. Stakeholders can see test statistics online.
If setting up the whole infrastructure for CI is prohibitively expensive (in terms of time) to you, you may consider deploying your test scripts on a shared machine or prepare VM with test scripts that your colleagues can download and run.
Is there any method to execute it from GitHub?
I don't think so. GitHub does not serve for remote script execution. It hosts Version Control System (VCS), so it serves for revision versioning.