Pulling requires out of often called methods.

While debugging this hairy situation, I had hooked require to try to
figure out sequencing. These requires were called thousands upon
thousands of times, creating a lot of noise and having no benefit
other than a possible savings of a few millisecond on an already slow
startup.

Signed-off-by: Ryan Davis <zenspider@chef.io>

lib/inspec/control_eval_context.rb

@@ -2,6 +2,7 @@
 # author: Christoph Hartmann
 require 'inspec/dsl'
 require 'inspec/dsl_shared'
+require 'rspec/core/dsl'
 
 module Inspec
   #
@@ -19,7 +20,6 @@ module Inspec
     # @param [ResourcesDSL] resources_dsl which has all resources to attach
     # @return [RuleContext] the inner context of rules
     def self.rule_context(resources_dsl, profile_id)
-      require 'rspec/core/dsl'
       Class.new(Inspec::Rule) do
         include RSpec::Core::DSL
         with_resource_dsl resources_dsl

lib/inspec/metadata.rb

@@ -5,6 +5,7 @@ require 'rubygems/version'
 require 'rubygems/requirement'
 require 'semverse'
 require 'utils/spdx'
+require 'erb'
 
 module Inspec
   # Extract metadata.rb information
@@ -198,7 +199,6 @@ module Inspec
 
     def self.from_yaml(ref, content, profile_id, logger = nil)
       res = Metadata.new(ref, logger)
-      require 'erb'
       res.params = YAML.load(ERB.new(content).result)
       res.content = content
       finalize(res, profile_id, {}, logger)

lib/inspec/runner.rb

@@ -11,6 +11,7 @@ require 'inspec/metadata'
 require 'inspec/config'
 require 'inspec/dependencies/cache'
 require 'inspec/dist'
+require 'inspec/runner_rspec'
 # spec requirements
 
 module Inspec
@@ -52,7 +53,6 @@ module Inspec
       @cache = Inspec::Cache.new(@conf[:vendor_cache])
 
       @test_collector = @conf.delete(:test_collector) || begin
-        require 'inspec/runner_rspec'
         RunnerRspec.new(@conf)
       end