FIX it isn't sometimes escape.

e.g.

% v1.3.0
1> bbmustache:render(<<"{{{message}}world}">>, #{"message"=>"<s>hello</s>"}).  
<<"{<s>hello</s>world}">>

% v1.3.1
2> bbmustache:render(<<"{{{message}}world}">>, #{"message"=>"<s>hello</s>"}).  
<<"{&lt;s&gt;hello&lt;/s&gt;, }">>