Fix issue 28 by self closing the br tag

Author: strivedi183

lib/arbre/html/tag.rb

@@ -130,7 +130,7 @@ def indent(open_tag, child_content, close_tag)
       end
 
       def self_closing_tag?
-        %w|meta link|.include?(tag_name)
+        %w|br link meta|.include?(tag_name)
       end
 
       def no_child?

spec/arbre/integration/html_spec.rb

@@ -187,6 +187,12 @@
       }.to_s).to eq("<link rel=\"stylesheet\"/>\n")
     end
 
+    it "should self-close br tags" do
+      expect(arbre {
+        br
+      }.to_s).to eq("<br/>\n")
+    end
+
   end
 
   describe "html safe" do