Create dist for python3.7 per default (and add help)

Both Intra2net systems and avocado are now running on python3.7

diff --git a/make_dist.py b/make_dist.py
index 6b99299..2ee7fa7 100755 (executable)
--- a/make_dist.py
+++ b/make_dist.py
@@ -210,8 +210,11 @@ def main():
     see module doc for more info
     """
     release = None
-    py_versions = ['3.3', '3.6']
+    py_versions = ['3.7', ]
     if len(sys.argv) > 1:
+        if sys.argv[1] in ('--help', '-h'):
+            print('make_dist.py [releasename [py-ver1 [py-ver2...]]]')
+            print('  e.g.: make_dist.py featuretest 3.7')
         release = sys.argv[1].replace('-', '_')
     else:
         release = check_output(['git', 'log', '--pretty=format:%h', '-n', '1'],