extract list claims filters to translations.py
elminate active/waiting duration hybrid properties
ttl & timeout use MaybeTimedelta for marshaling
extract output marshaling dicts to new module
cleanup marshaling

- no more marshal_with
- explicitly marshal successful responses (not errors)
- calculate Location header more robustly
- return url field
specify return code for failed 'waiting' -> 'active' request
rename metadata to user_data in spec
specify parameter names more precisely in spec
specify HTTP headers in spec
POST/PATCH/PUT params should be in body
clarify filterable resource names
Merge pull request #6 from mark-burnett/refactor-query-translation

Cleanup filtering and marshaling code
add offset and limit tests
verify that the first url was skipped
Merge pull request #7 from mark-burnett/clarify-spec

Clarify spec
rename limited_response to offset_response
Merge pull request #9 from mark-burnett/limit-offset

Add offset and limit tests