add main HPI executable

my/__main__.py

@@ -0,0 +1,30 @@
+class Modes:
+    HELLO = 'hello'
+
+
+def parser():
+    from argparse import ArgumentParser
+    p = ArgumentParser('Human Programming Interface', epilog='''
+Tool for HPI.
+
+Work in progress, will be used for config management, troubleshooting & introspection
+''')
+    sp = p.add_subparsers(dest='mode')
+    sp.add_parser(Modes.HELLO, help='TODO just a stub, remove later')
+    return p
+
+
+def main():
+    p = parser()
+    args = p.parse_args()
+    mode = args.mode
+    if mode == Modes.HELLO:
+        print('hi')
+    else:
+        import sys
+        p.print_usage()
+        sys.exit(1)
+
+
+if __name__ == '__main__':
+    main()