Added scikit-learn as a test dependency, since it's used by an example
Added scikit-learn as a test dependency, since it's used by an example

ctk3b/mdtraj,rmcgibbo/mdtraj,rmcgibbo/mdtraj,msultan/mdtraj,jchodera/mdtraj,dwhswenson/mdtraj,ctk3b/mdtraj,leeping/mdtraj,gph82/mdtraj,mattwthompson/mdtraj,tcmoore3/mdtraj,gph82/mdtraj,mdtraj/mdtraj,dwhswenson/mdtraj,msultan/mdtraj,leeping/mdtraj,tcmoore3/mdtraj,dwhswenson/mdtraj,tcmoore3/mdtraj,rmcgibbo/mdtraj,msultan/mdtraj,mattwthompson/mdtraj,mdtraj/mdtraj,jchodera/mdtraj,mattwthompson/mdtraj,ctk3b/mdtraj,ctk3b/mdtraj,leeping/mdtraj,mattwthompson/mdtraj,jchodera/mdtraj,ctk3b/mdtraj,jchodera/mdtraj,leeping/mdtraj,msultan/mdtraj,tcmoore3/mdtraj,mdtraj/mdtraj,gph82/mdtraj