Quick fix to ensure that billing doesn't fail if the crown is not set

for the service.

The letters rates for cronw and non crown are the same. It would be nice
to remove the need for crown but for now this is a quick fix.

requirements.txt

@@ -47,14 +47,14 @@ alembic==1.5.8
 amqp==1.4.9
 anyjson==0.3.3
 attrs==20.3.0
-awscli==1.19.35
+awscli==1.19.36
 bcrypt==3.2.0
 billiard==3.3.0.23
 bleach==3.3.0
 blinker==1.4
 boto==2.49.0
-boto3==1.17.35
-botocore==1.20.35
+boto3==1.17.36
+botocore==1.20.36
 certifi==2020.12.5
 chardet==4.0.0
 click==7.1.2
@@ -66,6 +66,7 @@ geojson==2.5.0
 govuk-bank-holidays==0.8
 greenlet==1.0.0
 idna==2.10
+importlib-metadata==3.7.3
 Jinja2==2.11.3
 jmespath==0.10.0
 kombu==3.0.37
@@ -87,13 +88,15 @@ pytz==2021.1
 PyYAML==5.4.1
 redis==3.5.3
 requests==2.25.1
-rsa==4.7.2
+rsa==4.5
 s3transfer==0.3.6
 Shapely==1.7.1
 six==1.15.0
 smartypants==2.0.1
 soupsieve==2.2.1
 statsd==3.3.0
+typing-extensions==3.7.4.3
 urllib3==1.26.4
 webencodings==0.5.1
 Werkzeug==1.0.1
+zipp==3.4.1