Fixes npm error "Invalid version"
Fixes npm error "Invalid version"

npm requires version to follow semantic versioning as described here :
http://semver.org/ (npm uses node-semver to check versions).
Although 1.3.3.7 is fun and all, it is incompatible with semantic
versioning. I could have replaced 1.3.3.7 with 1.3.3-7, which would
have been ok regarding semver, but I prefered to use the latest tag.

mattjmattj/drawingboard.js,mattjmattj/drawingboard.js