Use hoe-bundler to create Gemfile

This is for Travis CI, so it can install all the dependencies before running
the tests. hoe-travis is supposed to do this, but it doesn't work, as it uses
a Rake task, and Rake doesn't run at all until the required dependencies are
installed.

Bundler users (like me) will also appreciate being able to use `bundle install`
to get all the dependencies needed to work on Racc.

Remove the `isolate` gem, as Bundler does everything it does. Also, the 2 don't
play well together when running tests.

In future, when any dependencies are changed, make sure to run
`rake bundler:gemfile` and commit the results.

.gitignore

@@ -11,3 +11,8 @@ target
 lib/racc/cparse-jruby.jar
 racc.gemspec
 TAGS
+
+# For Bundler
+.bundle
+Gemfile.lock
+Gemfile.local

Gemfile

@@ -0,0 +1,19 @@
+# -*- ruby -*-
+
+# DO NOT EDIT THIS FILE. Instead, edit Rakefile, and run `rake bundler:gemfile`.
+
+source "https://rubygems.org/"
+
+
+gem "rdoc", "~>4.0", :group => [:development, :test]
+gem "rake", "~>10.4", :group => [:development, :test]
+gem "rake-compiler", ">=0.4.1", :group => [:development, :test]
+gem "minitest", "~>4.7", :group => [:development, :test]
+gem "hoe", "~>3.14", :group => [:development, :test]
+gem "hoe-debugging", "~>1.2", :group => [:development, :test]
+gem "hoe-doofus", "~>1.0", :group => [:development, :test]
+gem "hoe-git", "~>1.6", :group => [:development, :test]
+gem "hoe-gemspec", "~>1.0", :group => [:development, :test]
+gem "hoe-bundler", "~>1.2", :group => [:development, :test]
+
+# vim: syntax=ruby

Rakefile

@@ -5,7 +5,7 @@ require 'hoe'
 
 gem 'rake-compiler', '>= 0.4.1'
 
-Hoe.plugin :debugging, :doofus, :git, :isolate, :gemspec
+Hoe.plugin :debugging, :doofus, :git, :gemspec, :bundler
 $: << '.' # instead of require_relative for 1.8 compatibility
 
 def java?
@@ -23,9 +23,17 @@ HOE = Hoe.spec 'racc' do
   self.history_file      = 'ChangeLog'
   self.readme_file       = 'README.rdoc'
 
+  dependency 'rake',          '~> 10.4',  :developer
   dependency 'rake-compiler', '>= 0.4.1', :developer
   dependency 'minitest',      '~> 4.7',   :developer # stick to stdlib's version
 
+  dependency 'hoe',           '~> 3.14',  :developer
+  dependency 'hoe-debugging', '~> 1.2',   :developer
+  dependency 'hoe-doofus',    '~> 1.0',   :developer
+  dependency 'hoe-git',       '~> 1.6',   :developer
+  dependency 'hoe-gemspec',   '~> 1.0',   :developer
+  dependency 'hoe-bundler',   '~> 1.2',   :developer
+
   if java?
     self.spec_extras[:platform]   = 'java'
   else