Bumped version to 7.0.0a0 for release

Author: davidbrochart

docs/changelog.rst

@@ -4,8 +4,9 @@
 Changes in Jupyter Client
 =========================
 
-6.2.0
-=====
+7.0.0a0
+=======
+- Add back ``block`` keyword argument to ``get_msg`` (:ghpull:`641`)
 - Fix threaded client and fix qtconsole issues (:ghpull:`638`)
 - Drop Python 3.5 and pin Python >= 3.6.1 (:ghpull:`636`)
 - Use pre-commit for code style (:ghpull:`631`)
@@ -14,6 +15,10 @@ Changes in Jupyter Client
 - Add KernelManager subclass tests (:ghpull:`626`)
 - Add type annotations, refactor sync/async (:ghpull:`623`)
 
+6.2.0
+=====
+- Yanked (PyPI) and marked as broken (conda)
+
 6.1.13
 ======
 - Yanked (PyPI) and marked as broken (conda)

jupyter_client/_version.py

@@ -1,4 +1,4 @@
-version_info = (6, 2, 0, "dev")
+version_info = (7, 0, 0, "a0")
 __version__ = ".".join(map(str, version_info))
 
 protocol_version_info = (5, 3)