Merge pull request #28 from jgennis/local-variant

Add CreateLocalVariations to BottupUpMutatorContext.
diff --git a/module_ctx.go b/module_ctx.go
index 1cdb51c..76d3977 100644
--- a/module_ctx.go
+++ b/module_ctx.go
@@ -390,6 +390,7 @@
 
 	AddDependency(module Module, name string)
 	CreateVariations(...string) []Module
+	CreateLocalVariations(...string) []Module
 	SetDependencyVariation(string)
 }