Allowed params names with : at the beginning

PHP supports binding params with `:` and without. As we add it always
we should strip it out first before checking the name with regular
expression, and add it at the end.

Author: michalbundyra

src/Adapter/Driver/Pdo/Pdo.php

@@ -304,6 +304,7 @@ public function getPrepareType()
     public function formatParameterName($name, $type = null)
     {
         if ($type === null && ! is_numeric($name) || $type == self::PARAMETERIZATION_NAMED) {
+            $name = ltrim($name, ':');
             // @see https://bugs.php.net/bug.php?id=43130
             if (preg_match('/[^a-zA-Z0-9_]/', $name)) {
                 throw new Exception\RuntimeException(sprintf(

test/Adapter/Driver/Pdo/PdoTest.php

@@ -53,6 +53,7 @@ public function getParamsAndType()
             [ '123foo', Pdo::PARAMETERIZATION_NAMED, ':123foo' ],
             [ 1, Pdo::PARAMETERIZATION_NAMED, ':1' ],
             [ '1', Pdo::PARAMETERIZATION_NAMED, ':1' ],
+            [ ':foo', null, ':foo' ],
         ];
     }