Switched to gem which command to locate gem path rather than open-gem

CHANGELOG.rdoc

@@ -2,6 +2,7 @@
 Bugs fixes:
   - Return unique filenames from Linux listener (Marian Schubert)
   - Guard.get_guard_class return wrong class when loaded nested class. (koshigoe)
+  - Fixed open-gem/gem_open dependency problem by using `gem which` to locate guards gem path
 
 == 0.3.0 (Jan 19, 2011)
 

guard.gemspec

@@ -20,7 +20,6 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'guard-rspec', '~> 0.1.9'
 
   s.add_dependency 'thor',     '~> 0.14.6'
-  s.add_dependency 'open_gem', '~> 1.4.2'
 
   s.files        = Dir.glob('{bin,images,lib}/**/*') + %w[LICENSE README.rdoc]
   s.executable   = 'guard'

lib/guard.rb

@@ -88,7 +88,7 @@ module Guard
     end
 
     def locate_guard(name)
-      `gem open guard-#{name} --latest --command echo`.chomp
+      `gem which guard/#{name}`.chomp
     rescue
       UI.error "Could not find 'guard-#{name}' gem path."
     end