chore: release 0.6

Author: zsquareplusc

DEVELOPER.rst

@@ -8,7 +8,7 @@ Creating a release
 - Ensure that the ``version`` in ``serial_asyncio/__init__.py`` is updated
   and in the form of major.minor[.patchlevel]
 - Ensure all changes, including version, is committed then create a tag with
-  the exact same value as the version (e.g. "0.5")
+  the same value as the version but prefixed with a ``v`` (e.g. "v0.5")
 - Push to GitHub, merge into master if it is a branch. The GitHub Actions
   are set-up to build the default branch.
 - Inspect the built wheel and tar.gz files for correctness, test.

serial_asyncio/__init__.py

@@ -25,7 +25,7 @@
 except ImportError:
     termios = None
 
-__version__ = '0.5'
+__version__ = '0.6'
 
 
 class SerialTransport(asyncio.Transport):