Make shell scripts executable

[strickvl]

A user in slack reported that some of the shell scripts used internally were not executable. This was causing problems, so this PR fixes that for all the shell scripts by making them all executable. (chmod +x ... for all of them).

Pre-requisites

Please ensure you have done the following:

• I have read the CONTRIBUTING.md document.
• If my change requires a change to docs, I have updated the documentation
  accordingly.
• I have added tests to cover my changes.
• I have based my new branch on develop and the open PR is targeting
  develop. If your branch wasn't based on develop read
  Contribution guide on rebasing branch to develop.

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)
• Other (add details above)