Merge pull request #552 from ably/fix/httpx-version

Upgrade httpx version

Author: sacOO7

poetry.lock

@@ -32,7 +32,11 @@ python = "^3.7"
 # Mandatory dependencies
 methoddispatch = "^3.0.2"
 msgpack = "^1.0.0"
-httpx = { version = "^0.24.1", extras = ["http2"] }
+httpx = [
+  { version = "^0.24.1", python = "~3.7" },
+  { version = "^0.25.0", python = "^3.8" },
+]
+h2 = "^4.1.0" # required for httx package, HTTP2 communication
 
 # Optional dependencies
 pycrypto = { version = "^2.6.1", optional = true }