Introduces the file clone_utilities.py and the methods:
generate_clone_command(): Which generates a string representing a git clone command to be used by subprocess based on command line arguments, manifest file contents and cache status
clone_single_repository(): Which clones a single repository and checks out the ref specified in the project manifest file.
Updates the clone_repos() method in common_repo_functions.py to leverage the new clone_single_repository() method.
Introduces the file clone_utilities.py and the methods:
generate_clone_command(): Which generates a string representing a git clone command to be used by subprocess based on command line arguments, manifest file contents and cache status
clone_single_repository(): Which clones a single repository and checks out the ref specified in the project manifest file.
Updates the clone_repos() method in common_repo_functions.py to leverage the new clone_single_repository() method.
Fixes: #221