Change endpoint responses where there are marshalling, unmarshalling

or param errors to raise invalid data exception. That will cause
those responses to be handled in by errors.py, which will log
the errors.

Set most of schemas to strict mode so that marshmallow will raise
exception rather than checking for errors in return tuple from load.

Added handler to errors.py for marshmallow validation errors.

app/errors.py

@@ -4,9 +4,10 @@ from flask import (
 )
 from sqlalchemy.exc import SQLAlchemyError, DataError
 from sqlalchemy.orm.exc import NoResultFound
+from marshmallow import ValidationError
 
 
-class InvalidData(Exception):
+class InvalidRequest(Exception):
 
     def __init__(self, message, status_code):
         super().__init__()
@@ -22,7 +23,12 @@ class InvalidData(Exception):
 
 def register_errors(blueprint):
 
-    @blueprint.app_errorhandler(InvalidData)
+    @blueprint.app_errorhandler(ValidationError)
+    def validation_error(error):
+        current_app.logger.error(error)
+        return jsonify(result='error', message=error.messages), 400
+
+    @blueprint.app_errorhandler(InvalidRequest)
     def invalid_data(error):
         response = jsonify(error.to_dict())
         response.status_code = error.status_code