Release Notes for v1.1.1

Version description of the v1.1.1 release of ICESat-2 SlideRule.

New Features

Added ipxapi.py module to Python client to support ICEPyx users.
GeoDataFrames are now sorted by time. Time is also used as the index. (APIs affected: atl06, atl06p, atl03s, atl03sp).

The issue with the server crashing in version 1.1.0 was resolved.
- In version v1.0.6, support for NSIDC Cumulus was added; but it had a dormant bug in the implementation.
- Each server maintains up-to-date AWS credentials for NSIDC resources in S3 by authenticating to the earthdata login servers and getting API tokens that last for 1 hour. Every 30 minutes, each server re-authenticates and gets new tokens. For performance reasons, AWS clients are pre-allocated and re-used. The AWS clients are only cycled when new tokens arrive. The code that created new clients with the updated tokens had race-conditions in it where a deleted client could still be in use.
- The introduction of ATL08 processing in version 1.1.0 lengthed the amount of time a client was in use and therefore made the race-condition much more likely to occur.
- The race condition has been fixed in this version.

ATL08 classification can be supplied as a table or a string. 04bc5fb
Fixed out of bounds access caught by valgrind. 5af94a5
Changed name of Python bindings to srpybin to avoid naming conflicts with the SlideRule Python client. 0525c0b
Signed integer support added to Python bindings sliderule#84
Fixed bugs in s3cache I/O driver for H5Coro, and added support in Python bindings. 0170be8