Lambdarest

- add support for base64 encoded body
- fix errrors since readme tests have not been run for a while
- fix int casting (now casts to float first and then int)

**This is not a backwards compatible change.**

- Use query `schema.properties.query.properties.*` as type lookup for unpacking of query params to right types (including lists/singulars of strings/ints/floats/booleans)
- **not supporting json objects as values in query-params anymore** _use json body instead_

- Document exception handling behavior in README 66
- Supporting multiValueHeaders 65
- Reorganize documentation

- Fixed issue with empty dict being returned as is instead of being converted to string 63
- Fixed issue with schema validation for schemas with oneOf element 62

**This is not a backwards compatible change.**

- add support for scopes 60
- drop support for python 3.5
- drop tox for testing
- use poetry for packaging

**This is not a backwards compatible change.**

- minimally process standard lambda (dict) responses (pr 59)