Issues upgrading to 1.13.0 with ruby 2.2

[alagos]

I'm working in a ruby 2.2/rails 4.2 project (not my choice, sorry about that) and I've had some conflicts upgrading from 1.11.0 to 1.13.0, specifically a bunch of conflicts with nokogiri upgrade:

Bundler could not find compatible versions for gem "nokogiri":
  In Gemfile:
    capybara was resolved to 3.1.1, which depends on
      nokogiri (~> 1.8)

    caxlsx was resolved to 3.0.0, which depends on
      nokogiri (>= 1.8.2, ~> 1.8)

    rails (= 4.2.11.3) was resolved to 4.2.11.3, which depends on
      actionpack (= 4.2.11.3) was resolved to 4.2.11.3, which depends on
        rails-html-sanitizer (>= 1.0.2, ~> 1.0) was resolved to 1.3.0, which depends on
          loofah (~> 2.3) was resolved to 2.8.0, which depends on
            nokogiri (>= 1.5.9)

    rails_admin was resolved to 1.4.3, which depends on
      rack-pjax (>= 0.7) was resolved to 1.1.0, which depends on
        nokogiri (~> 1.5)

    rails (= 4.2.11.3) was resolved to 4.2.11.3, which depends on
      actionmailer (= 4.2.11.3) was resolved to 4.2.11.3, which depends on
        rails-dom-testing (>= 1.0.5, ~> 1.0) was resolved to 1.0.9, which depends on
          nokogiri (~> 1.6)

    quickbooks-ruby (~> 1.0) was resolved to 1.0.17, which depends on
      roxml (~> 4.0) was resolved to 4.1.1, which depends on
        nokogiri (>= 1.3.3)

    ruby-saml (~> 1.13.0) was resolved to 1.13.0, which depends on
      nokogiri (>= 1.10.5)

    sunspot_rails was resolved to 2.1.1, which depends on
      nokogiri

Bundler could not find compatible versions for gem "ruby":
  In Gemfile:
    ruby

    caxlsx was resolved to 3.0.0, which depends on
      nokogiri (>= 1.8.2, ~> 1.8) was resolved to 1.10.10, which depends on
        ruby (>= 2.3.0)

from this, it caught my attention that ruby-saml 1.13.0 depends on nokogiri >= 1.10.5, when due to the version restrictions, this should had been scoped between >= 1.9.1 and <= 1.10.0. Worth to mention my ruby version again:

┗ ruby -v
ruby 2.2.10p489 (2018-03-28 revision 63023) [x86_64-darwin19]

and the RUBY_VERSION variable in my rails console:

[31][12:43:19NZDT] pry(main)(deve)> RUBY_VERSION < '2.3'
=> true
[32][13:20:59NZDT] pry(main)(deve)> RUBY_VERSION
=> "2.2.10"

Regardless of that issue, ruby 2.2 support was dropped in Nokogiri 1.10.0, so the gemspec restriction should be something like:

  elsif RUBY_VERSION < '2.3'
    s.add_runtime_dependency('nokogiri', '>= 1.9.1', '< 1.10.0')

I´m working with a fork now, that probably isn't the solution you guys expect, but it works for me in the short term.

[pitbulk]

Can you provide a PR twith:

  elsif RUBY_VERSION < '2.1'
    s.add_runtime_dependency('nokogiri', '>= 1.5.10', '<= 1.6.8.1')
    s.add_runtime_dependency('json', '< 2.3.0')
  elsif RUBY_VERSION < '2.2'
    s.add_runtime_dependency('nokogiri', '>= 1.9.1', '< 1.10.0')
  elsif RUBY_VERSION < '2.3'  
    s.add_runtime_dependency('nokogiri', '>= 1.9.1', '<= 1.10.0')

[alagos]

I've just made a PR, but is a bit different as you asked for:

  elsif RUBY_VERSION < '2.2'
    s.add_runtime_dependency('nokogiri', '>= 1.9.1', '< 1.10.0')

but that will apply for versions lower than 2.2 (indeed I tried it locally and didn't work), so I did the change directly in RUBY_VERSION < '2.3'