Expose eigenvalues
Copy code from cluster mixin
Use `transform` instead of `predict`
Cleanup
Add a simple test to compare to sklearn
Merge pull request #210 from mpharrigan/pca

PCA Wrapper
Merge pull request #211 from mpharrigan/eigenvalues

Expose eigenvalues
Cached eigensystem results weren't being used
Merge pull request #213 from mpharrigan/eigenbug

Cached eigensystem results weren't being used