Roboleaf product configuration runner

The application rbcrun executes Starlark scripts that define Android product configurations.
See README.md for details.

Test: go test
Fixes: 180529448
Change-Id: I7d728b47d3f381b7052a0d7d51c9e698e5c2e316
diff --git a/tools/rbcrun/testdata/module2.star b/tools/rbcrun/testdata/module2.star
new file mode 100644
index 0000000..f6818a2
--- /dev/null
+++ b/tools/rbcrun/testdata/module2.star
@@ -0,0 +1,2 @@
+# Module loaded my load.star
+test = "module2"