Gemfile in instana-1.7.1 vs Gemfile in instana-1.7.2

@@ -11,18 +11,27 @@
   # Rack v2 dropped support for Ruby 2.2 and higher.
   if RUBY_VERSION < '2.2'
     gem 'rack', '< 2.0'
   end
   gem 'rack-test'
+
+  # public_suffix dropped support for Ruby 2.1 and earlier.
+  gem 'public_suffix', '< 3.0'
 end
 
 group :development do
   gem 'ruby-debug',   :platforms => [:mri_18, :jruby]
   gem 'debugger',     :platform  =>  :mri_19
-  gem 'byebug',       :platforms => [:mri_20, :mri_21, :mri_22, :mri_23, :mri_24]
+
   if RUBY_VERSION > '1.8.7'
     gem 'pry'
-    gem 'pry-byebug', :platforms => [:mri_20, :mri_21, :mri_22, :mri_23, :mri_24]
+
+    if RUBY_VERSION < '2.2'
+      gem 'byebug', '< 9.1.0'
+      gem 'pry-byebug'
+    else
+      gem 'pry-byebug'
+    end
   else
     gem 'pry', '0.9.12.4'
   end
 end