slaprunner/test: create needed directories so PromiseLauncher don't crash

software/slaprunner/test/software_v1/instance.cfg

 [buildout]
-parts = instance
+parts =
+  directory
+  instance
 
 eggs-directory = ${buildout:eggs-directory}
 develop-eggs-directory = ${buildout:develop-eggs-directory}
 
+[directory]
+recipe = plone.recipe.command
+home = $${buildout:directory}
+etc = $${:home}/etc
+plugins = $${:etc}/plugin
+command = mkdir $${:etc} $${:plugins}
+
 [instance]
 recipe = plone.recipe.command
 command = echo -n 1 > $${buildout:directory}/version.txt

software/slaprunner/test/software_v2/instance.cfg

 [buildout]
-parts = instance
+parts =
+  directory
+  instance
 
 eggs-directory = ${buildout:eggs-directory}
 develop-eggs-directory = ${buildout:develop-eggs-directory}
 
+[directory]
+recipe = plone.recipe.command
+home = $${buildout:directory}
+etc = $${:home}/etc
+plugins = $${:etc}/plugin
+command = mkdir $${:etc} $${:plugins}
+
 [instance]
 recipe = plone.recipe.command
 command = echo -n 2 > $${buildout:directory}/version.txt