add test for renderability of Array.length via dot notation

test/_files/dot_notation.mustache

@@ -8,3 +8,4 @@
 <p>Zero: {{truthy.zero}}</p>
 <p>False: {{truthy.notTrue}}</p>
 <p>length of string should not be rendered: {{price.currency.name.length}}</p>
+<p>length of an array should be rendered: {{authors.length}}</p>

test/_files/dot_notation.txt

@@ -8,3 +8,4 @@
 <p>Zero: 0</p>
 <p>False: false</p>
 <p>length of string should not be rendered: </p>
+<p>length of an array should be rendered: 2</p>