Merge pull request #14 from pjialin/dependabot/pip/lxml-4.9.1

Bump lxml from 4.3.4 to 4.9.1

Author: pjialin

requirements.txt

@@ -16,7 +16,7 @@ hyperframe==5.2.0
 idna==2.8
 idna-ssl==1.1.0
 importlib-metadata==0.18
-lxml==4.3.4
+lxml==4.9.1
 more-itertools==7.1.0
 multidict==4.5.2
 packaging==19.0