Add rust toolchains

Signed-off-by: Ravago Jones <ravagojones@gmail.com>
Change-Id: I5f36ff152b01bbb628dea45175294cf7f52bb15f
diff --git a/tools/dependency_rewrite b/tools/dependency_rewrite
index 3cafe9b..cc1de8c 100644
--- a/tools/dependency_rewrite
+++ b/tools/dependency_rewrite
@@ -5,6 +5,7 @@
 rewrite dl.google.com/(.*) software.frc971.org/Build-Dependencies/dl.google.com/$1
 rewrite mirror.bazel.build/(.*) software.frc971.org/Build-Dependencies/mirror.bazel.build/$1
 rewrite nodejs.org/(.*) software.frc971.org/Build-Dependencies/nodejs.org/$1
+rewrite static.rust-lang.org/(.*) software.frc971.org/Build-Dependencies/static.rust-lang.org/$1
 allow golang.org
 
 allow software.frc971.org