Fix .dockerignore, add docker run and go vet tests in CI

[7h3-3mp7y-m4n]

Added files that were missing in .dockerignore..

Description

while building the image we did not see the score-k8s at his full potential, so after adding the rest of the file it works fine..

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• New chore (expected functionality to be implemented)

Checklist:

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• I've signed off with an email address that matches the commit author.

[mathieu-benoit]

Improve the catch of error if the container is not built/running properly.