Update to go 1.18 and upgrade dependencies

[rowanseymour]

No description provided.

[codecov-commenter]

Codecov Report

Merging #66 (ab95e92) into main (8c7d819) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main      #66   +/-   ##
=======================================
  Coverage   68.34%   68.34%           
=======================================
  Files           6        6           
  Lines         815      815           
=======================================
  Hits          557      557           
  Misses        148      148           
  Partials      110      110           

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