v0.8.0

• Make plugin loading more thread safe
• Enable basic fetch/test parallelization via the --fetch-degree and --test-degree options which default to 5 and 1 respectively
• Prefix certain lines of stdout to make it clear where data is coming from when parallelization is being used
• Add --version to --help output
• Use %ComSpec% to locate cmd.exe on windows
• Add ENV counterparts to the --foo-timeout and --foo-degree options
• Initial Perl6 -> Raku name change accommodations that allow the use of .rakutest and .rakumod
• Remove Zef::Repository::MetaCPAN
• No longer pass both -Ilib after -I. (just the later)