Bump version to 0.4.15

Changes since 0.4.14:

- Add `anneal_schedule` feature to `Client.solvers()` (feature-based
  solver selection)
- Docs updates and fixes

dwave/cloud/package_info.py

@@ -14,7 +14,7 @@
 
 __packagename__ = 'dwave-cloud-client'
 __title__ = 'D-Wave Cloud Client'
-__version__ = '0.4.14'
+__version__ = '0.4.15'
 __author__ = 'D-Wave Systems Inc.'
 __description__ = 'A minimal client for interacting with D-Wave cloud resources.'
 __url__ = 'https://github.com/dwavesystems/dwave-cloud-client'