Implement condition DSL negated test prefix (no_*)

* Allow no_* to be used for every tests in condition DSL:
  condition { no_has_env :shell, '/bin/sh' };
* Modify Test constructor to accept negated: named argument, implement
  #negated? and #pass?;
* Rename #success? to #verify in all test classes.

lib/producer/core/condition.rb

@@ -14,7 +14,7 @@ module Producer
 
       def met?
         return !!@return_value if @tests.empty?
-        @tests.each { |t| return false unless t.success? }
+        @tests.each { |t| return false unless t.pass? }
         true
       end
 

lib/producer/core/condition/dsl.rb

@@ -13,6 +13,9 @@ module Producer
             define_method(keyword) do |*args|
               @tests << klass.new(@env, *args)
             end
+            define_method("no_#{keyword}") do |*args|
+              @tests << klass.new(@env, *args, negated: true)
+            end
           end
         end
 

lib/producer/core/test.rb

@@ -3,9 +3,18 @@ module Producer
     class Test
       attr_reader :env, :arguments
 
-      def initialize(env, *arguments)
+      def initialize(env, *arguments, negated: false)
         @env        = env
         @arguments  = arguments
+        @negated    = negated
+      end
+
+      def negated?
+        @negated
+      end
+
+      def pass?
+        verify ^ negated?
       end
     end
   end

lib/producer/core/tests/has_env.rb

@@ -2,7 +2,7 @@ module Producer
   module Core
     module Tests
       class HasEnv < Test
-        def success?
+        def verify
           env.remote.environment.has_key? arguments.first.to_s.upcase
         end
       end

lib/producer/core/tests/has_file.rb

@@ -2,7 +2,7 @@ module Producer
   module Core
     module Tests
       class HasFile < Test
-        def success?
+        def verify
           env.remote.fs.has_file? arguments.first
         end
       end