Don't make --url required.

Use the reasonable default of the prod site.

csv_uploader.py

diff --git a/csv_uploader.py b/csv_uploader.py
index 1f69bbf..44edd54 100755
--- a/csv_uploader.py
+++ b/csv_uploader.py
@@ -33,7 +33,7 @@
 argparser = argparse.ArgumentParser(description='GCI CSV Task Uploader.')
 argparser.add_argument('--apikey', type=str, nargs='?', required=True,
                        help='api key')
-argparser.add_argument('--url', type=str, nargs='?', required=True,
+argparser.add_argument('--url', type=str, nargs='?',
                        default='https://codein.withgoogle.com',
                        help='server url')
 argparser.add_argument('--publish', action='store_true',

list_tasks.py

diff --git a/list_tasks.py b/list_tasks.py
index 6876aaf..0a52bcb 100755
--- a/list_tasks.py
+++ b/list_tasks.py
@@ -23,7 +23,7 @@
 argparser = argparse.ArgumentParser(description='GCI CSV Task Uploader.')
 argparser.add_argument('--apikey', type=str, nargs='?', required=True,
                        help='api key')
-argparser.add_argument('--url', type=str, nargs='?', required=True,
+argparser.add_argument('--url', type=str, nargs='?',
                        default='https://codein.withgoogle.com',
                        help='server url')
 argparser.add_argument('--debug', action='store_true',