update CHANGELOG and bump version to 4.2.2

(also snuck in a simplification of local pre-commit hooks)

.pre-commit-config.yaml

@@ -18,7 +18,12 @@ repos:
     hooks:
     -   id: flake8
         exclude: elasticapm\/utils\/wrapt|build|src|tests|dist|conftest.py|setup.py
--   repo: https://github.com/elastic/apm-agent-python
-    rev: 86fca8c04e6d638ed 
+-   repo: local
     hooks:
-    - id: license-header-check
+    -   id: license-header-check
+        name: License header check
+        description: Checks the existance of license headers in all Python files
+        entry: ./tests/scripts/license_headers_check.sh
+        exclude: "(elasticapm\/utils\/wrapt\/.*|tests\/utils\/stacks\/linenos.py)"
+        language: script
+        types: [python]

CHANGELOG.md

@@ -1,9 +1,10 @@
 # Changelog
 
-## Unreleased
-[Check the diff](https://github.com/elastic/apm-agent-python/compare/v4.2.1...master)
+## v4.2.2
+[Check the diff](https://github.com/elastic/apm-agent-python/compare/v4.2.1...v4.2.2)
  * fixed an issue with Celery and the prefork worker pool (#444)
  * fixed an issue when running uwsgi without a master process (#446)
+ * fixed an issue with gevent/eventlet on Python 3.7 (#451, #454)
  * introduced `IntervalTimer` and use it instead of `threading.Timer` (#452)
  * added license header check as pre-commit hook (#456)
 

elasticapm/version.py

@@ -28,5 +28,5 @@
 #  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 #  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-__version__ = (4, 2, 1)
+__version__ = (4, 2, 2)
 VERSION = ".".join(map(str, __version__))