Merge pull request #535 from LCSB-BioCore/mk-lh-remove-duplicate

clean up the change_objective! overloading, add doc
3 jobs for lh-remove-duplicate in 10 minutes and 3 seconds (queued for 6 seconds)
Status Name Job ID Coverage
  Test
passed docker:julia1.7 #319871

00:08:15

passed format #319872
privileged

00:01:19

 
  Documentation
passed doc-tests-pr:julia1.7 #319873

00:01:47