Fix test selection scope expansion

Restores the pre expression based test selection since the change was
unintentional made.

lib/mutant/context/scope.rb

@@ -97,7 +97,7 @@ module Mutant
       #
       def match_expressions
         name_nesting.each_index.reverse_each.map do |index|
-          Expression.parse_strict(name_nesting.take(index.succ).join(NAMESPACE_DELIMITER))
+          Expression.parse_strict("#{name_nesting.take(index.succ).join(NAMESPACE_DELIMITER)}*")
         end
       end
       memoize :match_expressions

lib/mutant/strategy.rb

@@ -73,7 +73,7 @@ module Mutant
     def tests(subject)
       subject.match_expressions.each do |match_expression|
         tests = all_tests.select do |test|
-          test.expression.prefix?(match_expression)
+          match_expression.prefix?(test.expression)
         end
         return tests if tests.any?
       end

spec/unit/mutant/subject_spec.rb

@@ -3,8 +3,8 @@ require 'spec_helper'
 describe Mutant::Subject do
   let(:class_under_test) do
     Class.new(described_class) do
-      def match_expression
-        'match'
+      def expression
+        Mutant::Expression.parse('Test')
       end
     end
   end
@@ -34,6 +34,6 @@ describe Mutant::Subject do
   describe '#identification' do
     subject { object.identification }
 
-    it { should eql('match:source_path:source_line') }
+    it { should eql('Test:source_path:source_line') }
   end
 end