Fix: replace buildpack version with tag

Author: rwos

buildpack.toml

@@ -3,7 +3,7 @@ api = "0.7"
 [buildpack]
   id = "static-buildpack"
   name = "Static Buildpack"
-  version = "dev"
+  version = "__replace__"
   homepage = "https://www.runway.horse/docs/"
   keywords = ["hugo", "mdbook"]
   description = "A buildpack for Hugo & mdbook (for Runway)"
@@ -14,4 +14,4 @@ api = "0.7"
 
 [metadata]
   include-files = ["bin/build", "bin/detect", "buildpack.toml"]
-  pre-package = "make package"
+  pre-package = "make package"