tests: Introduce running tests with GNU autotest in OpenBSC

The quality of the tests is of different value but it is good to
get started and improve from here.
diff --git a/openbsc/.gitignore b/openbsc/.gitignore
index c19c16a..37495cc 100644
--- a/openbsc/.gitignore
+++ b/openbsc/.gitignore
@@ -52,4 +52,10 @@
 tests/sms/sms_test
 tests/timer/timer_test
 
+tests/atconfig
+tests/package.m4
+tests/testsuite
+tests/testsuite.log
+
+
 src/openbsc.cfg*