Update dev depenencies

Author: andrew

split.gemspec

@@ -33,10 +33,10 @@ Gem::Specification.new do |s|
   s.add_dependency 'sinatra',         '>= 1.2.6'
   s.add_dependency 'simple-random',   '>= 0.9.3'
 
-  s.add_development_dependency 'bundler',     '~> 1.10'
+  s.add_development_dependency 'bundler',     '~> 1.14'
   s.add_development_dependency 'simplecov',   '~> 0.12'
   s.add_development_dependency 'rack-test',   '~> 0.6'
-  s.add_development_dependency 'rake',        '~> 11.1'
+  s.add_development_dependency 'rake',        '~> 12'
   s.add_development_dependency 'rspec',       '~> 3.4'
   s.add_development_dependency 'pry',         '~> 0.10'
   s.add_development_dependency 'fakeredis',   '~> 0.6.0'