TDY

All of these changes are fixes and tidy ups - no new functionality.

b6f6a55 Exit if unpack fails - it's no good continuing
3c82bc2 Drop deprecated GitLab badge for now
07bbc42 Pep8
35c3e23 Log arch mismatch
45ef539 Exit if attempt to deploy unbuilt system
f0a7992 Check fields in morph files, and exit if something odd is found
2f25e36 Compose subsystems before systems
03c09d0 Default to warn on missing install-commands
88e2d88 Merge pull request #229 from leeming/leeming/issue-218
d6cd8f0 Adding in exception handler to catch Unicode Encoding error and handle unicode filepaths
8b6012d Dump contents of dn