MIC 1.1.0

• revamp of the essential_agreement function to allow a more robust, flexible,
  and explicit approach to dealing with censored values. Now, essential_agreement
  (and compare_mic) have tolerate_censoring and tolerate_matched_censoring
  arguments to control how censored values are handled. The default values should
  be appropriate for most situations where the user is comparing an investigational
  method to a gold standard method.
• compare_mic is faster when only one ab is provided
• subset S3 method added for mic_validation
• plot.mic_validation now properly matches dilutions on the lower end of the
  scale
• droplevels.mic_validation method added that allows unnecessary MIC levels
  in a validation object to be dropped
• tidy_patric_meta_data was missing MICs when laboratory_typing_method was
  "MIC" (see 81c69f0)
• pull_patric_genomes now takes an ab argument to only download strains
  where the specified antibiotic was tested
• kmer counting is now case insensitive
• compatibility with AMR v3.0