Last namespace separator is not removed

Because the count function was used to determine the length of the FQNN the last character
was not correctly determined. This was remedied by replacing the count function with strlen.

Fixes #26

Author: mvriel

src/Types/Context.php

@@ -51,7 +51,7 @@ public function __construct($namespace, array $namespaceAliases = [])
             if ($fqnn[0] === '\\') {
                 $fqnn = substr($fqnn, 1);
             }
-            if ($fqnn[count($fqnn)-1] === '\\') {
+            if ($fqnn[strlen($fqnn) - 1] === '\\') {
                 $fqnn = substr($fqnn, 0, -1);
             }