test/buttons: added pexpect script

tests/buttons/Makefile

@@ -4,3 +4,6 @@ include ../Makefile.tests_common
 USEMODULE += xtimer
 
 include $(RIOTBASE)/Makefile.include
+
+test:
+	tests/01-run.py

tests/buttons/tests/01-run.py

+#!/usr/bin/env python3
+
+# Copyright (C) 2017 Freie Universität Berlin
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+
+import os
+import sys
+
+sys.path.append(os.path.join(os.environ['RIOTBASE'], 'dist/tools/testrunner'))
+import testrunner
+
+def testfunc(child):
+    child.expect_exact("On-board button test")
+    index = child.expect([
+        r"\[FAILED\] no buttons available!",
+        r" -- Available buttons: \d+"
+    ])
+
+    if index == 1:
+        child.expect_exact("[SUCCESS]")
+
+if __name__ == "__main__":
+    sys.exit(testrunner.run(testfunc))