cloud/bmaas/server/api: add gomod placeholder for go mod tidy

Change-Id: Iae1b568db08947b9314b735fa404cf43a2d37445
Reviewed-on: https://review.monogon.dev/c/monogon/+/1027
Tested-by: Jenkins CI
Reviewed-by: Sergiusz Bazanski <serge@monogon.tech>
diff --git a/cloud/bmaas/server/api/gomod-generated-placeholder.go b/cloud/bmaas/server/api/gomod-generated-placeholder.go
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/cloud/bmaas/server/api/gomod-generated-placeholder.go