Fix #6 Pre-1.0 upgrades should not be safe

rockspecs/semver-1.2.1-1.rockspec

@@ -0,0 +1,25 @@
+package = "semver"
+version = "1.2.1-1"
+source = {
+   url = "git://github.com/kikito/semver.lua.git",
+}
+description = {
+   summary = "An implementation of semantic versioning (semver.org 2.0.0) in Lua",
+   detailed = [[
+      See details in http://semver.org
+   ]],
+   license = "MIT",
+   homepage = "https://github.com/kikito/semver.lua"
+}
+dependencies = {
+   "lua >= 5.1"
+}
+
+build = {
+  type = "none",
+  install = {
+    lua = {
+      "semver.lua"
+    },
+  }
+}