slapos-sr-testing: Use slapos.core from the repository

The test system requires to adapt to changes in slapos.core rapidly,
and so it has use the most recent version.

software/slapos-sr-testing/software.cfg

@@ -15,8 +15,8 @@ extends =
   ./buildout.hash.cfg
 
 parts =
-  slapos-cookbook
   eggs
+  slapos-cookbook
   template
 
 [setup-develop-egg]
@@ -102,16 +102,27 @@ setup = ${slapos-repository:location}/software/nextcloud/test/
 egg = slapos.test.nextcloud
 setup = ${slapos-repository:location}/software/turnserver/test/
 
+[slapos.core-repository]
+<= git-clone-repository
+repository = https://lab.nexedi.com/master/slapos.core.git
+branch = master
+
+[slapos.core-setup]
+<= setup-develop-egg
+egg = slapos.core
+setup = ${slapos.core-repository:location}
+
 [eggs]
 recipe = zc.recipe.egg
 eggs =
+  ${lxml-python:egg}
+  ${slapos.core-setup:egg}
   ${pillow-python:egg}
   erp5.util
   ${python-pynacl:egg}
   ${python-cryptography:egg}
   ${bcrypt:egg}
   slapos.libnetworkcache
-  slapos.core
   supervisor
   ${slapos.cookbook-setup:egg}
   ${slapos.test.caddy-frontend-setup:egg}
@@ -156,6 +167,8 @@ output = ${buildout:directory}/template.cfg
 mode = 640
 
 [versions]
+# slapos.core is used from the clone always
+slapos.core =
 # Various needed versions
 Pillow = 5.3.0
 PyNaCl = 1.3.0