Safely serialize configuration JSON (#1605)

* Safely serialize configuration JSON

Co-Authored-By: Tom Kralidis <tomkralidis@gmail.com>

* Revert "Safely serialize configuration JSON"

This reverts commit 36feb067ee6f87e61955852dc48994f075806370.

* Add test for datetime with Admin API

* Safely serialize configuration JSON

---------

Co-authored-by: Tom Kralidis <tomkralidis@gmail.com>

pygeoapi/admin.py

@@ -128,8 +128,8 @@ class Admin(API):
 
         # Preserve env variables
         LOGGER.debug('Reading env variables in configuration')
-        raw_conf = get_config(raw=True)
-        conf = get_config()
+        raw_conf = json.loads(to_json(get_config(raw=True)))
+        conf = json.loads(to_json(get_config()))
         patch = make_patch(conf, raw_conf)
 
         LOGGER.debug('Merging env variables')

tests/data/admin/resource-post.json

@@ -32,6 +32,9 @@
             90
           ],
           "crs": "http://www.opengis.net/def/crs/OGC/1.3/CRS84"
+        },
+        "temporal": {
+            "begin": "2018-02-14T11:11:11Z"
         }
       },
       "providers": [