tests: add DejaGNU framework

DejaGNU seems to be the 'standard' GNU test framework (which by itself
doesn't say much), but it seems relatively usable and the "remote
system" capabilities might come in handy for virtualisation-based tests
for kernel interactions or something.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/tests/.gitignore b/tests/.gitignore
index 93e886c..8baea0a 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -10,6 +10,10 @@
 *.lo
 *.la
 *.libs
+*.bak
+*.log
+*.sum
+*.xml
 .arch-inventory
 .arch-ids
 aspathtest
@@ -27,3 +31,4 @@
 testprivs
 testsig
 teststream
+site.exp