Allow "metadata" kwarg to be optional.

Author: Peter Amstutz

cwltool/main.py

@@ -103,8 +103,9 @@ def arg_parser():  # type: () -> argparse.ArgumentParser
                         default="turtle")
 
     parser.add_argument("--eval-timeout",
-                        help="Time to wait for a Javascript expression to evaluate before giving an error.",
-                        type=float)
+                        help="Time to wait for a Javascript expression to evaluate before giving an error, default 20s.",
+                        type=float,
+                        default=20)
 
     exgroup = parser.add_mutually_exclusive_group()
     exgroup.add_argument("--print-rdf", action="store_true",

cwltool/process.py

@@ -228,7 +228,7 @@ class Process(object):
 
     def __init__(self, toolpath_object, **kwargs):
         # type: (Dict[str, Any], **Any) -> None
-        self.metadata = kwargs["metadata"]  # type: Dict[str,Any]
+        self.metadata = kwargs.get("metadata", {})  # type: Dict[str,Any]
         self.names = None  # type: avro.schema.Names
         names = schema_salad.schema.make_avro_schema(
             [SCHEMA_FILE, SCHEMA_ANY], schema_salad.ref_resolver.Loader({}))[0]