Log Message:
devel/ruby-parslet: update to 2.0.0

Update to ruby-parslet to 2.0.0.

= 2.0 / 16Feb2020

  This release is essentially what is called a 'done' release, meaning I consider
  that parslet meets its goals and doesn't need (much) more evolution.

  - prsnt? and absnt? are now finally banned into oblivion. Wasting vocals for
    the win.

  - Because Ruby 2.6 broke Integer() conversion for non-Strings, we've removed
    to_int for slices; to assert Integer type, you must now 'Integer(slice.to_s)'.
    (Broken? How? Integer now (2.6) calls to_int - and when that fails - to_i.
    A class that has both will never raise an exception. Incientially, this makes
    String a unicorn class.)