chore: release 1.21.0 (#54)

* updated CHANGELOG.md [ci skip]

* updated setup.cfg [ci skip]

* updated setup.py

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bd798ae..5d4ea78 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-api-core/#history
 
+## [1.21.0](https://www.github.com/googleapis/python-api-core/compare/v1.20.1...v1.21.0) (2020-06-18)
+
+
+### Features
+
+* allow credentials files to be passed for channel creation ([#50](https://www.github.com/googleapis/python-api-core/issues/50)) ([ded92d0](https://www.github.com/googleapis/python-api-core/commit/ded92d0acdcde4295d0e5df05fda0d83783a3991))
+
 ### [1.20.1](https://www.github.com/googleapis/python-api-core/compare/v1.20.0...v1.20.1) (2020-06-16)
 
 
diff --git a/setup.py b/setup.py
index 7f65fd0..efa4a12 100644
--- a/setup.py
+++ b/setup.py
@@ -22,7 +22,7 @@
 
 name = "google-api-core"
 description = "Google API client core library"
-version = "1.20.1"
+version = "1.21.0"
 # Should be one of:
 # 'Development Status :: 3 - Alpha'
 # 'Development Status :: 4 - Beta'