Helios-sdk

Fix `Collections.add_image()` and `Collections.remove_image()` methods that broke due to changes in 3.0.0 release.

FeatureCollections

* Simplified inheritance structure.
* Simplified FeatureCollections (for each API).
* Iterate over features by accessing the `features` property. This property gives access to the list of individual features.
* `"X"FeatureCollection` no longer inherits `RecordCollection` and instead is composed of an instance of `RecordCollection`.

python
results = helios.Cameras().index(state='new york')

Access individual features and filter.
video_cams = [f for f in results.features if f.video]

Access raw records.
good_queries = results.records.succeeded

Convenience properties are still available and will combine attributes of every feature in the collection.
ids = results.id


New `data_utils` module.

* A data_utils moduls was added to helios.utilities.
* Currently contains a single function to concatenate feature collections.
* This will handle merging the features and raw record data.

python
results = helios.Cameras().index(state='new york')
results2 = helios.Cameras().index(state='maryland')
combined = helios.utilities.data_utils.concatenate_feature_collections((results, results2))


Breaking Changes

FeatureCollections are no longer directly iterable.

You will need to explicitely iterate over the `features` property in the `FeatureCollection` results.

Example of deprecated usage:

python
results = helios.Cameras().index(state='new york')

This no longer works.
video_cams = [f for f in results if f.video]


Example of new usage:

python
results = helios.Cameras().index(state='new york')

Use this.
video_cams = [f for f in results.features if f.video]


ImageCollection Properties

* `output_file` has changed to `output_files`.
* `name` has changed to `image_names`.

Deprecated credentials completely removed.

* You can no longer use the old format for credentials.
* The following are no longer valid:
* `HELIOS_KEY_ID`
* `HELIOS_KEY_SECRET`
* `HELIOS_API_URL`
* `~/.helios_auth`

Python 3 only

* Various checks for Python 2/3 compatibility have been removed and version 3 is for Python version 3.6+ as specified in setup.py.

Added deprecation warning for Python 2.

Final Release Supporting Python 2

This release marks the end of Python 2 support. Moving forward, all versions of the SDK will only support Python 3.

This final Python 2 release will remain in PyPI and running `pip install helios-sdk` with Python 2 will continue to function for this final release.

Config File
* Added a config file that will be auto-created upon next import.
json
{
"general": {
"max_threads": 32
},
"requests": {
"retries": 3,
"timeout": 5,
"ssl_verify": true
},
"session": {
"token_expiration_threshold": 60
}
}

* `token_expiration_threshold` is minutes.

Other Improvements
* Logging can be turned on with a call to `helios.add_stderr_logger()`
* This allows the user to define custom logging schemes without conflict.
* Various bug fixes and stability improvements.
* Fixed situation where an extra forward slash was being generated in API URLs. On some systems this caused network exceptions.