remove acquaintances in the library

Link: https://github.com/GeneAssembly/biosal/issues/434
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
remove acquaintance API

Link: https://github.com/GeneAssembly/biosal/issues/434
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>