Actually check for dav_headers
Raise proper error messages when using discovery

Init arg introspection didn't properly occur when the user used
collection discovery to create the storages. Instead the raw exception
from the inside of s.discover bubbled up.
Validate general section.

Fix #100
Don't try to show pretty error messages for ^C
Merge pull request #102 from t-8ch/tls_fingerprints

Tls fingerprints

Fix #100
Don't produce overlapping output or prompts.

See #96 and #101
Make CI scripts more readable.
Fix typo
Revert "Tls fingerprints"
Merge pull request #104 from untitaker/revert-102-tls_fingerprints

Revert "Tls fingerprints"
Revert "Revert "Tls fingerprints""