Pyhocon

* Update pyparsing requirement from ~=2.0 to >=2,<4 (ecederstrand) [296]
* Fixes for dict substitution (USSX-Hares) [292]
* Fix: Tests on Windows (USSX-Hares) [291]
* Fix broken overrides (afanasev) [287]

* Resolve namespace package (yifeitao) [264]
* Update pyparsing requires lock to be more strict [275]

* Adding the resolve method to resolve substitution keys in 1 config tree with another config tree (borissmidt) [266]
* Support serializing timedelta and relativedelta to string (hocon, json etc.) (gabis-precog) [263]
* Upgrade to GitHub-native Dependabot (dependabot-preview) [260]
* Process substitution overrides in order (JettJones) [257]
* Fix duration parsing in lists (olii) [255]
* Add support for Python 3.9 and fix deprecation warning (olii) [254]

* Rewrite the logic to resolve package-relative paths so we can remove the "asset" library (klamann) [247]

* fix include error with chinese strings (xinghaixu) [240]
* Glob-pattern Includes (USSX-Hares) [236]
* Fix parsing of durations/periods (olii) [237]
* Fix config_parser.py docstrings (LysanderGG) [235]

* Add test for include substitution (gpoulin) [217]
* Fix self references when environment variables exist (anujkumar93) [219]
* Remove inactive Gitter channel from README (scottj97) [255]
* Fix STR_SUBSTITUTION, because ConfigSubstitution has no function raw_str (manso92) [227]
* Add support for package include (mrijken) [228]
* Fix required(file()) syntax (jrouly) [229]