update CHANGELOG and bump version to 5.5.1

Author: basepi

CHANGELOG.asciidoc

@@ -26,6 +26,13 @@ endif::[]
 [[release-notes-5.x]]
 === Python Agent version 5.x
 
+[[release-notes-5.5.1]]
+==== v5.5.1
+
+[float]
+===== Bug fixes
+* Fixed Starlette middleware when capturing request body while the content-type header is absent {pull}763[#763]
+
 [[release-notes-5.5.0]]
 ==== v5.5.0
 

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__ = (5, 5, 0)
+__version__ = (5, 5, 1)
 VERSION = ".".join(map(str, __version__))