Bump httpx from 0.19.0 to 0.20.0 (#31)

Bumps [httpx](https://github.com/encode/httpx) from 0.19.0 to 0.20.0.
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.19.0...0.20.0)

---
updated-dependencies:
- dependency-name: httpx
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

poetry.lock

@@ -10,7 +10,7 @@ repository = "https://github.com/supabase/postgrest-py"
 
 [tool.poetry.dependencies]
 python = "^3.7"
-httpx = "^0.19.0"
+httpx = ">=0.19,<0.21"
 deprecation = "^2.1.0"
 
 [tool.poetry.dev-dependencies]