Add package-log.json for headless build. Set to 4.0.4

This is probably fine as a patch release. Even tough files have been
moved around, the API is still the same.

CHANGES.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## 4.1.0 (Unreleased)
+## 4.0.4 (Unreleased)
 
 - Use [Lerna](https://lernajs.io/) to create the @converse/headless package
 - Use ES2015 modules instead of UMD.

src/headless/package-lock.json

@@ -0,0 +1,13 @@
+{
+	"name": "@converse/headless",
+	"version": "4.0.3",
+	"lockfileVersion": 1,
+	"requires": true,
+	"dependencies": {
+		"lodash": {
+			"version": "4.17.10",
+			"resolved": "https://registry.npmjs.org/lodash/-/lodash-4.17.10.tgz",
+			"integrity": "sha512-UejweD1pDoXu+AD825lWwp4ZGtSwgnpZxb3JDViD7StjQz+Nb/6l093lx4OQ0foGWNRoc19mWy7BzL+UAK2iVg=="
+		}
+	}
+}