Geedim

- Add support for Landsat 4 & 5 collections
- Cloud/shadow masking and compositing fix for non-native scales
- Masking performance improvement

- Fix Landsat7 SLE masking
- Remove noise from Sentinel2 shadow mask

- CLI and API options added for selecting the resampling method
- Default EE masks (where surface reflectance == 0) incorporated into shadow mask
- Fixed search stats to reflect validity of region rather than image
- Reflectance scaling (--scale-refl) removed
- Unit tests for checking image content

- Unnecessary mask and scale-refl options removed from search API and CLI
- Unit tests clean previous downloads and overwrite by default
- Github workflows now run on python 3.6 and 3.x (latest) only

First release