YAML's double-quoted strings interpret backslash escapes, so a
Windows path like C:\Users\white\AppData\... reads \U as the start
of a Unicode escape and fails on the first non-hex character with
"unknown escape character at line 4 column 34". Single-quoted YAML
strings pass backslashes through verbatim; only embedded single
quotes need escaping by doubling.

Apply the same pattern the Vault conductor config has used for a
while: single-quote both data_root_path and the lair connection_url,
escape embedded single quotes.

Bumps to 0.2.0-beta12.