baseDir should be relative to the GulpFile - not the CSS file being processed.

The newest version of `gulp-ruby-sass` places its work-in-progress files in a faraway temp directory, rendering `file.src` useless for finding images.
Update to 0.1.2
Merge pull request #11 from maranomynet/patch-1

baseDir should be relative to the GulpFile - not the CSS file