erp5: Add eggs to enforce datetime rfc in jsonschema

stack/erp5/buildout.cfg

@@ -557,6 +557,10 @@ eggs = ${neoppod:eggs}
   zope.globalrequest
   waitress
 
+# JSON Schema Validation
+  strict-rfc3339
+  jsonschema[format]
+
 # parameterizing the version of the generated python interpreter name by the
 # python section version causes dependency between this egg section and the
 # installation of python, which we don't want on an instance
@@ -756,3 +760,7 @@ beautifulsoup4 = 4.8.2
 WebOb = 1.8.5
 soupsieve = 1.9.5
 eggtestinfo = 0.3
+strict-rfc3339 = 0.7
+webcolors = 1.10
+rfc3987 = 1.3.8
+jsonpointer = 2.1