Simplify printing requirements in error messages

These are all `DepProxy`'s which already provide the same string
representation, no need to use `SharedHelpers.pretty_dependency`.

bundler/lib/bundler/resolver.rb

@@ -300,7 +300,7 @@ def verify_gemfile_dependencies_are_found!(requirements)
         elsif source = @source_requirements[name]
           specs = source.specs[name]
           versions_with_platforms = specs.map {|s| [s.version, s.platform] }
-          message = String.new("Could not find gem '#{SharedHelpers.pretty_dependency(requirement)}' in #{source}#{cache_message}.\n")
+          message = String.new("Could not find gem '#{requirement}' in #{source}#{cache_message}.\n")
           message << if versions_with_platforms.any?
             "The source contains the following versions of '#{name}': #{formatted_versions_with_platforms(versions_with_platforms)}"
           else
@@ -355,7 +355,7 @@ def version_conflict_message(e)
 
           trees.sort_by {|t| t.reverse.map(&:name) }
         end,
-        :printable_requirement => lambda {|req| SharedHelpers.pretty_dependency(req) },
+        :printable_requirement => lambda {|req| req.to_s },
         :additional_message_for_conflict => lambda do |o, name, conflict|
           if name == "bundler"
             o << %(\n  Current Bundler version:\n    bundler (#{Bundler::VERSION}))
@@ -389,7 +389,7 @@ def version_conflict_message(e)
             metadata_requirement = name.end_with?("\0")
 
             o << "Could not find gem '" unless metadata_requirement
-            o << SharedHelpers.pretty_dependency(conflict.requirement)
+            o << conflict.requirement.to_s
             o << "'" unless metadata_requirement
             if conflict.requirement_trees.first.size > 1
               o << ", which is required by "