Automatically generate rust tests and doctests

Change-Id: I685d6905d8861aa3368c46eda0e783497e88b581
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/tools/build_rules/autocxx.bzl b/tools/build_rules/autocxx.bzl
index 4046068..5cadf2b 100644
--- a/tools/build_rules/autocxx.bzl
+++ b/tools/build_rules/autocxx.bzl
@@ -252,7 +252,7 @@
         crate_features = None,
         crate_name = None,
         gen_debug = None,
-        docs = True):
+        **kwargs):
     """A macro to generate Rust <-> C++ interop code with autocxx.
 
     Creates the following rules:
@@ -344,5 +344,5 @@
         ],
         compile_data = [gen_compile_data_name],
         rustc_env_files = [gen_env_files_name],
-        docs = docs,
+        **kwargs
     )