- [FIXED] Enable proxy support for session cookie and IAM authenticat…

…ion.

- [FIXED] Type of `sinceSeq` can be also a `String` besides an `Integ…

…er`.

- [DEPRECATED] This library is now deprecated and will be EOL on Dec 31 2021.
- [IMPROVED] - Document IDs and attachment names are now rejected if they could cause an unexpected
  Cloudant request. We have seen that some applications pass unsantized document IDs to SDK functions
  (e.g. direct from user requests). In response to this we have updated many functions to reject
  obviously invalid paths. However, for complete safety applications must still validate that
  document IDs and attachment names match expected patterns.

- [NEW] Add migration guide to the newly supported cloudant-java-sdk …

…(coordinates: com.ibm.cloud:cloudant).

- [FIXED] Allow `$and`, `$or`, and `$nor` operator selectors to be used with only one expression selector.

- [FIXED] Connection leak regression introduced in 2.18.0 caused by n…

…ot closing streams from

  successful session response bodies.
- [UPGRADED] Optional OkHttp dependency to version 3.12.12.

- [NEW] Add getter for total row count to `AllDocsResponse`

- [NEW] Added `DbInfo#getSizes()` for access to improved sizes information.
- [FIXED] Corrected `DbInfo#getDiskSize()` to work with `sizes` object if `disk_size` is unavailable.
- [FIXED] `ViewMultipleRequest` updated to preferentially use view `queries` format URL instead of
  deprecated format.

- [FIXED] Create an array of strings for QueryBuilder.fields() when a…

… single field is provided.

- [FIXED] Potential NPE creating exception messages.
- [IMPROVED] Return exceptions directly from IAM token request failures instead of logging and
  deferring the request to the service with no credentials. The exception type is the same, but
  the message and cause are more clear and a round trip is avoided.
- [IMPROVED] Prevent multiple session renewal requests happening simultaneously because some auth
  types apply limits to the number of requests that can be made.
- [IMPROVED] Documented that for some database versions a call to get continuous changes may block
  when there are no changes available immediately.
- [UPGRADED] Optional OkHttp dependency to version 3.12.5.

- [NEW] Added `com.cloudant.client.api.model.DbInfo#getDocDelCountLon…

…g()` to return

  deleted document count as a `long` instead of a `String`.
- [DEPRECATED] `com.cloudant.client.api.model.DbInfo#getDocDelCount()`.

- [NEW] Added database partition metadata fields for partitioned inde…

…x count/limit.

- [NEW] Added replication selector support.

- [NEW] Added option for client to authenticate with IAM token server.

- [NEW] Added partitioned database support.
- [FIXED] Updated the default IAM token server URL.

- [NEW] Add `purge_seq` getter on `DbInfo` class that returns sequenc…

…e value as `String`.

- [DEPRECATED] `com.cloudant.client.api.model.DbInfo#getPurgeSeq()`.