Require psych in Rakefile to avoid syck error when compiling gem

[foobacca]

From memory I'm not sure psych is available in ruby 1.8. If so this should at least be wrapped in a version check.

[5long]

Psych is not available in 1.8.

I made a different attempt in #16: just keep using Syck until either

• 1.8 support is dropped

Or

• Make Psych a hard dependency of sup

[gauteh]

There is a similar case here: ruhoh/ruhoh.rb#77

I guess Psych is the future, could there be made a conditional dependency on it for <1.9.2?

Migrating to Psych might require some config-file updating.

Regards, gaute

[5long]

+1 to migrate to Psych. But I'd like to postpone it until we figure out how to migrate config files properly(either via documentation or code, and ruling out all runtime differences, which would be tough). The current code base assumes only Syck is used. I think it's better to merge #16 to get a release soon.

[gauteh]

This one at least is not the right way to go ;)