Gracefully handle case where RSpec is not installed in Rakefile

Rakefile

@@ -1,9 +1,13 @@
 require "rubygems"
-require "spec/rake/spectask"
 
 begin
   require 'jeweler'
-
+rescue LoadError
+  desc "Install gem using sudo"
+  task(:install) do
+    $stderr.puts "Jeweler not available. `gem install jeweler` to install this gem"
+  end
+else
   Jeweler::Tasks.new do |s|
     s.name      = "arel"
     s.authors   = ["Bryan Helmkamp", "Nick Kallen"]
@@ -16,10 +20,14 @@ begin
   end
 
   Jeweler::RubyforgeTasks.new
-rescue LoadError
-  puts "Jeweler not available. Install it with: gem install jeweler"
 end
 
+begin
+  require "spec/rake/spectask"
+rescue LoadError
+  desc "Run specs"
+  task(:spec) { $stderr.puts '`gem install rspec` to run specs' }
+else
   desc "Run specs using RCov (uses mysql database adapter)"
   Spec::Rake::SpecTask.new(:coverage) do |t|
     t.spec_files =
@@ -52,6 +60,7 @@ task :spec => ["check_dependencies", "spec:sqlite3", "spec:mysql", "spec:postgre
 
   desc "Default task is to run specs"
   task :default => :spec
+end
 
 desc 'Removes trailing whitespace'
 task :whitespace do