Fix watcher test for Ruby 3

[Sixeight]

before	after

Why

• Now unit test fails on Ruby 3
  • ArgumentError: wrong number of arguments (given 2, expected 1) (here)
• Keyword arguments are now separated from positional arguments on Ruby 3
  • FileUtils.touch cannot accept Hash as optional argument.

What

• Use keyword argument instead of Has as optional argument
  • FileUtils.touch accepts keyword argument since Ruby 2.4 (commit)
  • Spring supports Ruby 2.4 over.

Other fails

• Acceptance test fails on undef Rais 5.1
  • Fix acceptance test for under rails 5.1 #630
• Environment setup fails on Ruby 2.4.x
  • sprockets requires Ruby version >= 2.5.0. The current ruby version is 2.4.6.354.
  • Officially support Ruby 2.4.x ?
• Environment set fails on Rails 5.2 with Ruby 2
  • /home/travis/.rvm/gems/ruby-head/gems/activesupport-5.2.4.4/lib/active_support/messages/metadata.rb:17:in wrap': wrong number of arguments (given 2, expected 1) (ArgumentError)`
  • Maybe rails matter, should ignore this patter of test.

Related

• Is Ruby 2.7 supported? #625
  • Now, test on 2.4, 2.5, 2.6 and 3.0 (ruby-head)
  • Should we test on 2.7?