Add test for limit on intermediate certificates

Inspired by test code provided by Nicholas Wilson in PR #351.

The test will fail if someone sets MAX_INTERMEDIATE_CA to a value larger than
18 (default is 8), which is hopefully unlikely and can easily be fixed by
running long.sh again with a larger value if it ever happens.

Current behaviour is suboptimal as flags are not set, but currently the goal
is only to document/test existing behaviour.
diff --git a/tests/data_files/dir-maxpath/12.crt b/tests/data_files/dir-maxpath/12.crt
new file mode 100644
index 0000000..91ef9b0
--- /dev/null
+++ b/tests/data_files/dir-maxpath/12.crt
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----