Do final internal renameing

A little minor change, by moving the CodiMD version header in its own
middleware. Should simplify to determine the version number of the
Backend in future.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

lib/web/middleware/codiMDVersion.js

@@ -0,0 +1,10 @@
+'use strict'
+
+const config = require('../../config')
+
+module.exports = function (req, res, next) {
+  res.set({
+    'CodiMD-Version': config.version
+  })
+  return next()
+}