Implicit subject should not use .new with modules

Fixes GitHub issue https://github.com/icy-arctic-fox/spectator/issues/6

spec/subject_spec.cr

@@ -2,6 +2,8 @@ require "./spec_helper"
 
 class Base; end
 
+module SomeModule; end
+
 Spectator.describe "Subject" do
   subject { Base.new }
 
@@ -10,4 +12,12 @@ Spectator.describe "Subject" do
       expect(subject).to be_a(Base)
     end
   end
+
+  context "module" do
+    describe SomeModule do
+      it "sets the implicit subject to the module" do
+        expect(subject).to be(SomeModule)
+      end
+    end
+  end
 end

src/spectator/dsl/groups.cr

@@ -19,12 +19,18 @@ module Spectator
         %source = ::Spectator::Source.new({{_source_file}}, {{_source_line}})
         ::Spectator::SpecBuilder.start_group({{description}}, %source)
 
-        {% if (what.is_a?(Path) || what.is_a?(Generic)) && what.resolve? %}
+        {% if (what.is_a?(Path) || what.is_a?(Generic)) && (described_type = what.resolve?) %}
           macro described_class
-            {{what}}
+            {{described_type.name}}
           end
 
-          subject { described_class.new }
+          subject do
+            {% if described_type < Reference || described_type < Value %}
+              described_class.new
+            {% else %}
+              described_class
+            {% end %}
+          end
         {% else %}
           def _spectator_implicit_subject(*args)
             {{what}}