add under-construction release directories to gitignore
add under-construction release directories to gitignore

GMOD/jbrowse,GMOD/jbrowse,nathandunn/jbrowse,nathandunn/jbrowse,nathandunn/jbrowse,GMOD/jbrowse,GMOD/jbrowse,GMOD/jbrowse,nathandunn/jbrowse,nathandunn/jbrowse