Update branch to check out on laptop
Require new version of PDMats

Backed out a change using `unwhiten_sym` for `updateLdb`.  Need to reexamine.
Add coefnames for fixed-effects to output

Includes a temporary copy of coefnames definition until new DataFrames package release.
Align display of random effects variances.
Modify .travis.yml to include the PDMats package in the checking run.
Merge pull request #18 from dmbates/PDMats

Use PDMats types instead of a Triangular matrix for λ elements