Cognite-sdk

Added
- Variety of useful helper functions for Sequence and SequenceData objects, including .column_ids and .column_external_ids properties, iterators and slice operators.
- Sequences insert_dataframe function.
- Sequences delete_range function.
- Support for external id column headers in datapoints.insert_dataframe()

Changed
- Sequences data retrieval now returns a SequenceData object.
- Sequences insert takes its parameters row data first, and no longer requires columns to be passed.
- Sequences insert now accepts tuples and raw-style data input.
- Sequences create now clears invalid fields such as 'id' in columns specification, so sequences can more easily re-use existing specifications.
- Sequence data function now require column_ids or column_external_ids to be explicitly set, rather than both being passed through a single columns field

Fixed
- Renamed Model.schedule_data_spec to Model.data_spec so the field from the API will be included on the object.
- Handling edge case in Sequences pagination when last datapoint retrieved is at requested end
- Fixing data points retrieval when count aggregates are missing
- Displays unexpected fields on error response from API when raising CogniteAPIError

Added
- Support for model hosting exposed through experimental client

Fixed
- Handling dynamic limits in Sequences API

Added
- Experimental client
- Support for sequences exposed through experimental client

Added
- Support for all endpoints in Cognite API
- Generator with hidden cursor for all resource types
- Concurrent writes for all resources
- Distribution of "core" sdk which does not depend on pandas and numpy
- Typehints for all methods
- Support for posting an entire asset hierarchy, resolving ref_id/parent_ref_id automatically
- config attribute on CogniteClient to view current configuration.

Changed
- Renamed methods so they reflect what the method does instead of what http method is used
- Updated documentation with automatically tested examples
- Renamed `stable` namespace to `api`
- Rewrote logic for concurrent reads of datapoints
- Renamed CogniteClient parameter `num_of_workers` to `max_workers`

Removed
- `experimental` client in order to ensure sdk stability.