Add tests for (named) bitstring to suite_asn1write
diff --git a/tests/data_files/server1.req.key_usage_empty b/tests/data_files/server1.req.key_usage_empty
new file mode 100644
index 0000000..1ac1bc3
--- /dev/null
+++ b/tests/data_files/server1.req.key_usage_empty
@@ -0,0 +1,17 @@
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