Strato-query

Adds
- Adds `SDJobRunner`, a utility object that allows for querying StratoDem Analytics models by creating jobs
python
from strato_query import SDJobRunner, authenticate_to_api

authenticate_to_api('my-api-token')

This loads a query set defined in the client portal for the Boston and Austin MSAs
df = SDJobRunner().load_df_from_job_pipeline(
model_id='5ADyVKql',
geolevel='METRO',
geoid_list=[14454, 12420]
)

Adds
- Adds support for `walktime_simple` and `walktime_destination_simple`

Adds
- Adds a new arg, `time_between_chunks`, to the `query_api_multiple` method
By default, this arg is set to `None`, which will preserve existing behavior for unchanged queries. When given a value, the method will sleep for the specified time after each chunk is POSTed, and will continue to do so until all chunks have been submitted. The method will not sleep after the final chunk

Related issues
- [121](https://github.com/StratoDem/strato-query/issues/121)

Adds
- Adds new query param classes:
- `APIMilesDistanceQueryParams`
- `APIDrivingDistanceQueryParams`
- `APIWalkingDistanceQueryParams`

Related issues
- [109](https://github.com/StratoDem/strato-query/issues/109)

Changes
- Checks specifically for a 520 error and immediately raises a timeout

Related issues
- [107](https://github.com/StratoDem/strato-query/issues/107)

Changes
- Changes the error raised when the max number of query retries has been exceeded so it more clearly alerts API users that a timeout has occurred.

Related issues
- [104](https://github.com/StratoDem/strato-query/issues/104)