Added benchmark-ips to the Gemfile

This allows me to use this Gem for benchmarking without having to
add/remove it every time.

Gemfile

@@ -270,6 +270,8 @@ group :development, :test do
   gem 'rubocop',  '~> 0.28.0',  require: false
   gem 'coveralls',  '~> 0.8.2', require: false
   gem 'simplecov', '~> 0.10.0', require: false
+
+  gem 'benchmark-ips', require: false
 end
 
 group :test do

Gemfile.lock

@@ -66,6 +66,7 @@ GEM
       ice_nine (~> 0.11.0)
       thread_safe (~> 0.3, >= 0.3.1)
     bcrypt (3.1.10)
+    benchmark-ips (2.3.0)
     better_errors (1.0.1)
       coderay (>= 1.0.0)
       erubis (>= 2.6.6)
@@ -795,6 +796,7 @@ DEPENDENCIES
   asciidoctor (~> 1.5.2)
   attr_encrypted (~> 1.3.4)
   awesome_print (~> 1.2.0)
+  benchmark-ips
   better_errors (~> 1.0.1)
   binding_of_caller (~> 0.7.2)
   bootstrap-sass (~> 3.0)