Localize notification_utils to the API

This changeset pulls in all of the notification_utils code directly into the API and removes it as an external dependency.  We are doing this to cut down on operational maintenance of the project and will begin removing parts of it no longer needed for the API.

Signed-off-by: Carlo Costino <carlo.costino@gsa.gov>

notifications_utils/timezones.py

@@ -0,0 +1,16 @@
+import os
+
+import pytz
+from dateutil import parser
+
+local_timezone = pytz.timezone(os.getenv("TIMEZONE", "America/New_York"))
+
+
+def utc_string_to_aware_gmt_datetime(date):
+    """
+    Date can either be a string, naïve UTC datetime or an aware UTC datetime
+    Returns an aware local datetime, essentially the time you'd see on your clock
+    """
+    date = parser.parse(date)
+    forced_utc = date.replace(tzinfo=pytz.utc)
+    return forced_utc.astimezone(local_timezone)