Remove spec command.

It had been added for backward compatibility, but it turns out it just
makes things more confusing. After the next release rspec 1 and rspec 2
can both be installed in the same environment, but to use rspec 1 you'll
need to use the spec command as follows:

  spec _1.3.0_ spec

rspec-core.gemspec

@@ -9,10 +9,11 @@ Gem::Specification.new do |s|
 
   s.required_rubygems_version = Gem::Requirement.new("> 1.3.1") if s.respond_to? :required_rubygems_version=
   s.authors = ["Chad Humphries", "David Chelimsky"]
-  s.date = %q{2010-06-27}
+  s.date = %q{2010-06-28}
+  s.default_executable = %q{rspec}
   s.description = %q{RSpec runner and example groups}
   s.email = %q{dchelimsky@gmail.com;chad.humphries@gmail.com}
-  s.executables = ["rspec", "spec"]
+  s.executables = ["rspec"]
   s.extra_rdoc_files = [
     "README.markdown"
   ]
@@ -29,7 +30,6 @@ Gem::Specification.new do |s|
      "VERSION",
      "autotest/discover.rb",
      "bin/rspec",
-     "bin/spec",
      "cucumber.yml",
      "features/command_line/example_name_option.feature",
      "features/command_line/exit_status.feature",
@@ -142,7 +142,7 @@ Gem::Specification.new do |s|
   s.rdoc_options = ["--charset=UTF-8"]
   s.require_paths = ["lib"]
   s.rubyforge_project = %q{rspec}
-  s.rubygems_version = %q{1.3.6}
+  s.rubygems_version = %q{1.3.7}
   s.summary = %q{rspec-core-2.0.0.beta.14}
   s.test_files = [
     "spec/autotest/failed_results_re_spec.rb",
@@ -185,7 +185,7 @@ Gem::Specification.new do |s|
     current_version = Gem::Specification::CURRENT_SPECIFICATION_VERSION
     s.specification_version = 3
 
-    if Gem::Version.new(Gem::RubyGemsVersion) >= Gem::Version.new('1.2.0') then
+    if Gem::Version.new(Gem::VERSION) >= Gem::Version.new('1.2.0') then
       s.add_development_dependency(%q<rspec-expectations>, [">= 2.0.0.beta.14"])
       s.add_development_dependency(%q<rspec-mocks>, [">= 2.0.0.beta.14"])
       s.add_development_dependency(%q<cucumber>, [">= 0.5.3"])