definePrim option wrongly called primId

Prim checks for `definePrim` (see https://github.com/requirejs/alameda/blob/ba40c4f0c9107c973d4f615791f3d58bcff3ae90/alameda.js#L1329), not `primId`
Merge pull request #6 from medimatrix/master

definePrim option wrongly called primId