handle empty arrays and trailing commas

examples/parse.rs

@@ -0,0 +1,23 @@
+use php_object_parser::parse;
+
+fn main() {
+    let source = r###"
+    array (
+        "double" => "quote",
+        'single' => 'quote',
+        "escaped" => "\"quote\"",
+        1 => 2,
+        "nested" => [
+            "sub" => "key",
+        ],
+        "array" => [1,2,3,4],
+        "bool" => false,
+        "negative" => -1,
+    )
+    "###;
+
+    match parse(source) {
+        Ok(result) => print!("{:#?}", result),
+        Err(err) => eprint!("{}", err),
+    }
+}