Deprecated printMatrix as Matrix.toString() provides the same
functionality. printMatrix is also not used within BioJava.
Convert org.biojava.bio.structure (main) in biojava3-structure project
to use slf4j.  Several of the print statements were left based on
intention of method
Merge remote-tracking branch 'upstream/master'
Merge pull request #192 from benjamintboyle/master

Update org.biojava.bio.structure (main) package in biojava3-structure project to use slf4j #155