DirExists checks if the given directory path exists.

FileExists checks if the given file path exists and is a regular file.

GetenvOrDefault behaves like `os.Getenv`, except it returns a specified default value if the key is not present in the environment.

IsDirEmpty checks if the given directory is empty.

Creates a new retry strategy that also reduces the time for when running in test.

Rename is like os.Rename in every way.

ExpandableString is a string that has ${foo} style references inside which can be evaluated.