Improvements
* use install.rm_rf for TemporaryDirectory cleanup (3425)
* improve handling of local dependency information (2107)
* add default channels to exports for Windows and Unix (4103)
* make subdir configurable (4178)
Bug Fixes
* fix conda/install.py single-file behavior (3854)
* fix the api->conda substitution (3456)
* fix silent directory removal (3730)
* fix location of temporary hard links of index.json (3975)
* fix potential errors in multi-channel export and offline clone (3995)
* fix auxlib/packaging, git hashes are not limited to 7 characters (4189)
* fix compatibility with requests >=2.12, add pyopenssl as dependency (4059)
* fix 3287 activate in 4.1-4.2.3 clobbers non-conda PATH changes (4211)
Non-User-Facing Changes
* fix open-ended test failures relating to python 3.6 release (4166)
* allow args passed to cli.main() (4193, 4200, 4201)
* test against python 3.6 (4197)