Fix relative log file creation

[jgeiger]

Passing a relative path for the log file doesn't work on a Mac, and possibly elsewhere. If the passed in log argument is not an absolute path, it will now prepend the DAEMON_ROOT.

Also, fix rspec deprecation warnings.

[coveralls]

Coverage decreased (-0.0%) when pulling 21ab7a819a16f221e60755dd8ae375d2ec3c373c on jgeiger:fix_relative_log_file into 73c131881326a61336a042060710ee084ccbc084 on kennethkalmer:master.

[kennethkalmer]

Windows issues aside, how about making it a little more flexible and provide users with a mechanism to outright replace the logger with their own configured instance of a logger that looks like a logger?

[marcbowes]

Should we just merge this as is? I'm inclined.

[kennethkalmer]

Let me take a spike at the alternative, if it goes well we can compare notes!