Gemfile in instana-1.7.4 vs Gemfile in instana-1.7.5

@@ -19,9 +19,10 @@
 end
 
 group :development do
   gem 'ruby-debug',   :platforms => [:mri_18, :jruby]
   gem 'debugger',     :platform  =>  :mri_19
+  gem 'stackprof'
 
   if RUBY_VERSION > '1.8.7'
     gem 'pry'
 
     if RUBY_VERSION < '2.2'