Resolve input paths for compression before passing them to the container

[kirkrodrigues]

... and minor logging fixes.

References

#29

Description

The container cannot compress relative paths since it does not know the root of the path. So instead, we:

• Resolve input paths passed to sbin/compress before passing them to the container.
• Raise an error if the user specifies relative paths in a list of paths for compression (sbin/compress --input-list).

Validation performed

• Compressed a relative path
• Tried to compress a list of relative paths and validated that an error was raised
• Compress a list of absolute paths