Bump attrs from 19.1.0 to 19.3.0 (#1329)

* Bump attrs from 19.1.0 to 19.3.0

Bumps [attrs](https://github.com/python-attrs/attrs) from 19.1.0 to 19.3.0.
- [Release notes](https://github.com/python-attrs/attrs/releases)
- [Changelog](https://github.com/python-attrs/attrs/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/python-attrs/attrs/compare/19.1.0...19.3.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

* Fix attr Deprecations

.devcontainer/devcontainer.json

@@ -6,7 +6,7 @@
 	"appPort": "9123:8123",
 	"runArgs": [
 		"-e",
-		"GIT_EDITOR=\"code --wait\"",
+		"GIT_EDITOR=code --wait",
 		"--privileged"
 	],
 	"extensions": [
@@ -28,4 +28,4 @@
 		"editor.formatOnType": true,
 		"files.trimTrailingWhitespace": true
 	}
-}
+}