One major, multiple minor changes to Database

Major:
- New update(umb) method as an interface to _update(umb), with
  convenience and safeguards.

Minor:
- New exception: UmbrellaValueError
- All datetime objects are cast naive
- Database._write(umbrellas) raises exception after performing recovery
- human_datetime includes seconds in output

1 files changed, 6 insertions, 0 deletions

diff --git a/jimbrella/exceptions.py b/jimbrella/exceptions.py
index 3162e02..2c62bc4 100644
--- a/jimbrella/exceptions.py
+++ b/jimbrella/exceptions.py
@@ -13,3 +13,9 @@ class UmbrellaStatusError(Exception):
     """
 
     pass
+
+
+class UmbrellaValueError(Exception):
+    """For when an admin enters an invalid value when modifying the database."""
+
+    pass