Update billing for the backend refactor
Update references to mach
remove reports.fields.DatespanField and use reports.filters.dates.DatespanFilter instead, see commit 9b2d36b87b368a0d9bd8314d88a2ba30e7fde5f0
Merge branch 'gc-dev' of github.com:dimagi/payments into gc-dev
Merge branch 'master' into gc-dev
Fix exception handling
Merge pull request #24 from dimagi/gc-dev

Update billing for backend refactor