chore: Fix Travis builds using appraisal gem

This commit fixes the Travis builds by using different gemfiles for different
versions of Ruby and some gem dependencies (notably rack 1.x and 2.x). These
gemfiles are managed by the `appraisal` gem.

It also switches our build matrix from testing with `jruby-head` to testing
with `jruby-9.0.5.0`, since `jruby-head` has some issues with `bundler` not
being installed.

In addition to these changes, I have also enabled Travis's caching feature for
Bundler. Hopefully this should speed up our test runs once the caches are
primed.

Author: md5

.travis.yml

@@ -1,31 +1,49 @@
 env:
   global:
     - JRUBY_OPTS="$JRUBY_OPTS --debug"
+
+sudo: false
 language: ruby
-script: bundle exec rspec
-before_install: gem update bundler
+cache: bundler
+
+before_install:
+  - gem update bundler
+  
+before_script:
+  - bundle update
+
+script:
+  - bundle exec rspec
+
+rvm:
+  - 1.9.3
+  - jruby-19mode
+  - 2.0.0
+  - 2.1.10
+  - 2.2.2
+  - 2.3.1
+  - jruby-9.0.5.0
+  - ruby-head
+
+gemfile:
+  - gemfiles/rack_1.gemfile
+  - gemfiles/rack_2.gemfile
+
 matrix:
-  include:
-    - rvm: 1.9.3
-      gemfile: Gemfile
-    - rvm: 2.0.0
-      gemfile: Gemfile
-    - rvm: 2.1
-      gemfile: Gemfile
-    - rvm: 2.2
-      gemfile: Gemfile
-    - rvm: 2.3.0
-      gemfile: Gemfile
-    - rvm: jruby-19mode
-      gemfile: Gemfile
-    - rvm: jruby-head
-      gemfile: Gemfile
-    - rvm: rbx-2
-      gemfile: Gemfile
-    - rvm: ruby-head
-      gemfile: Gemfile
   allow_failures:
-    - rvm: jruby-head
     - rvm: ruby-head
+
   fast_finish: true
-sudo: false
+
+  exclude:
+    - rvm: 1.9.3
+      gemfile: gemfiles/rack_2.gemfile
+
+    - rvm: jruby-19mode
+      gemfile: gemfiles/rack_2.gemfile
+
+    - rvm: 2.0.0
+      gemfile: gemfiles/rack_2.gemfile
+
+    - rvm: 2.1.10
+      gemfile: gemfiles/rack_2.gemfile

Appraisals

@@ -0,0 +1,7 @@
+appraise 'rack-1' do
+  gem 'rack', '~> 1.x'
+end
+
+appraise 'rack-2' do
+  gem 'rack', '~> 2.x'
+end

Gemfile

@@ -2,7 +2,14 @@ source 'https://rubygems.org'
 
 group :test do
   gem 'coveralls', '~> 0.8', '>= 0.8.13', require: false
+
+  # Lock coveralls dependencies to lower versions to work with older rubies
+  gem 'json', '~> 1.8'
+  gem 'tins', '~> 1.6.0'
+
   gem 'mime-types', '< 3'
 end
 
+gem 'appraisal'
+
 gemspec

gemfiles/rack_1.gemfile

@@ -0,0 +1,15 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal"
+gem "rack", "~> 1.x"
+
+group :test do
+  gem "coveralls", "~> 0.8", ">= 0.8.13", :require => false
+  gem "json", "~> 1.8"
+  gem "tins", "~> 1.6.0"
+  gem "mime-types", "< 3"
+end
+
+gemspec :path => "../"

gemfiles/rack_2.gemfile

@@ -0,0 +1,15 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal"
+gem "rack", "~> 2.x"
+
+group :test do
+  gem "coveralls", "~> 0.8", ">= 0.8.13", :require => false
+  gem "json", "~> 1.8"
+  gem "tins", "~> 1.6.0"
+  gem "mime-types", "< 3"
+end
+
+gemspec :path => "../"

omniauth-saml.gemspec

@@ -14,6 +14,7 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency 'omniauth', '~> 1.3'
   gem.add_runtime_dependency 'ruby-saml', '~> 1.3'
 
+  gem.add_development_dependency 'rake', '>= 10', '< 12'
   gem.add_development_dependency 'rspec', '~>3.4'
   gem.add_development_dependency 'simplecov', '~> 0.11'
   gem.add_development_dependency 'rack-test', '~> 0.6', '>= 0.6.3'