v1.1.8

• Add antibody configuration option. Setting a specific antibody for ChIP-seq will use appropriate
  settings for that antibody. See the documentation for supported antibodies.
• Add use_lowfreq_filter for forcing vardict to report variants with low allelic frequency,
  useful for calling somatic variants in panels with high coverage.
• Fix for checking for pre-existing inputs with python3.
• Add keep_duplicates option for ChIP/ATAC-seq which does not remove duplicates before peak calling.
  Defaults to False.
• Add keep_multimappers for ChIP/ATAC-seq which does not remove multimappers before peak calling.
  Defaults to False.
• Remove ethnicity as a required column in PED files.