fixtures.yml: Pull dependencies from git

This is the current best practice. In unit tests the .fixtures.yml will
be used and we're able to detect breaking changes in dependencies before
they are released. In acceptance tests the latest forge releases based
on metadata.json will be used.

Author: bastelfreak

.fixtures.yml

@@ -1,18 +1,10 @@
+---
 fixtures:
-  forge_modules:
-    icinga:
-      repo: icinga/icinga
-    stdlib:
-      repo: puppetlabs/stdlib
-    concat:
-      repo: puppetlabs/concat
-    apt:
-      repo: puppetlabs/apt
-    chocolatey:
-      repo: puppetlabs/chocolatey
-    zypprepo:
-      repo: puppet/zypprepo
-    yumrepo_core:
-      repo: puppetlabs-yumrepo_core
-      puppet_version: ">= 6.0.0"
-
+  repositories:
+    icinga: https://github.com/voxpupuli/puppet-icinga
+    stdlib: https://github.com/puppetlabs/puppetlabs-stdlib
+    concat: https://github.com/puppetlabs/puppetlabs-concat
+    apt: https://github.com/puppetlabs/puppetlabs-apt
+    chocolatey: https://github.com/puppetlabs/puppetlabs-chocolatey
+    zypprepo: https://github.com/voxpupuli/puppet-zypprepo
+    yumrepo_core: https://github.com/puppetlabs/puppetlabs-yumrepo_core