Adding basic testing workflow to check qudi-core installs.

[prithviulm]

Description

As suggested by @TobiasSpohn, a simple test to check that qudi-core installs properly can be helpful to identify issues with dependencies. This can be expanded to a basic check that the module manager loads as well. Also, there is another plan to do an automatic check that both qudi-core and qudi-iqo-modules pass their respective tests whenever a dependency has a version bump.

Motivation and Context

When preparing a release for Qudi, we often fix dependencies but there can be conflicts that are not easy to find without permuting various installations. Also, dependecies often undergo version bumps and can cause breaking changes that are hard to trace back. Running the tests when a version bump is detected would be helpful to isolate these incidents.

How Has This Been Tested?

The tests run as expected on Github Actions.

Types of changes

• Bug fix
• New feature
• Breaking change (Causes existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• I have documented my changes in /docs/changelog.md.
• My change requires additional/updated documentation.
• I have updated the documentation accordingly.
• I have added/updated the config example for any module docstrings as necessary.
• I have checked that the change does not contain obvious errors
  (syntax, indentation, mutable default values, etc.).
• I have tested my changes using 'Load all modules' on the default dummy configuration.
• All changed Jupyter notebooks have been stripped of their output cells.