fix(rockspecs) add missing, add dev, add updated 0.9.7

[Tieske]

fixes #118

Fixes several issues;

• Release 0.9.7 was missing the release rockspec in the repo.
• rockspec for 0.9.7 was bad, adds a fixed rockspec for 0.9.7-1 as replacement
• adds a "dev" rockspec to enable luarocks make from the repo, and as a baseline for new rockspecs

This can be merged and uploaded (no new release required);

luarocks upload rockspecs/pegasus-0.9.7-1.rockspec

Any new release; just copy the dev rockspec, rename it, and edit the version at the top of the file.