Fix deprecations and possible false positive issue in tests. (#781)

spec/draper/view_context/build_strategy_spec.rb

@@ -39,7 +39,7 @@ module Draper
         expect(controller.request).to be_nil
         strategy.call
         expect(controller.request).to be_an ActionController::TestRequest
-        expect(controller.params).to eq({})
+        expect(controller.params.to_h).to eq({})
 
         # sanity checks
         expect(controller.view_context.request).to be controller.request

spec/dummy/config/boot.rb

@@ -2,4 +2,4 @@ require 'rubygems'
 
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../../../Gemfile', __FILE__)
 
-require 'bundler/setup' if File.exists?(ENV['BUNDLE_GEMFILE'])
+require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])

spec/dummy/fast_spec/post_decorator_spec.rb

@@ -32,6 +32,6 @@ describe PostDecorator do
   end
 
   it "can't be passed implicitly to url_for" do
-    expect{decorator.link}.to raise_error
+    expect{decorator.link}.to raise_error ArgumentError
   end
 end