Add MM Auth test; add auth_action_str() function
Add basic MM Authentication test setup, with fake DB access and RAND_bytes().
So far implement simple tests for IO error during DB access and missing auth
entry.
To print the auth action during tests, add struct auth_action_names and
auth_action_str() inline function in auth.[hc].
diff --git a/openbsc/tests/Makefile.am b/openbsc/tests/Makefile.am
index 04b8e34..09298a3 100644
--- a/openbsc/tests/Makefile.am
+++ b/openbsc/tests/Makefile.am
@@ -1,4 +1,4 @@
-SUBDIRS = gsm0408 db channel mgcp gprs abis gbproxy trau subscr
+SUBDIRS = gsm0408 db channel mgcp gprs abis gbproxy trau subscr mm_auth
if BUILD_NAT
SUBDIRS += bsc-nat bsc-nat-trie