Removing more ruby 2 conditionals and fixing up Rakefile removing cruft

Author: jonmchan

Rakefile

@@ -2,7 +2,6 @@
 
 require 'bundler/gem_tasks'
 require 'rspec/core/rake_task'
-require 'rake/notes/rake_task'
 
 RSpec::Core::RakeTask.new(:spec)
 

spec/fabric/ec_crypto_suite_spec.rb

@@ -273,7 +273,6 @@
     end
 
     it 'creates a matching public key' do
-      skip('Test unsupported on ruby 2.x') if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('3.0.0')
       private_pkey = OpenSSL::PKey::EC.generate(crypto_suite.curve)
       public_pem = private_pkey.public_to_pem