Bump httplib2 from 0.18.0 to 0.19.0

Bumps [httplib2](https://github.com/httplib2/httplib2) from 0.18.0 to 0.19.0.
- [Release notes](https://github.com/httplib2/httplib2/releases)
- [Changelog](https://github.com/httplib2/httplib2/blob/master/CHANGELOG)
- [Commits](https://github.com/httplib2/httplib2/compare/v0.18.0...v0.19.0)

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -42,7 +42,7 @@ gpg==1.13.1
 gpiozero==1.5.1
 guizero==1.1.0
 haxor-news==0.4.3
-httplib2==0.18.0
+httplib2==0.19.0
 hyperlink==19.0.0
 idna==2.10
 incremental==17.5.0
@@ -119,7 +119,7 @@ relint==1.2.1
 requests-futures==1.0.0
 requests-toolbelt==0.9.1
 requests==2.24.0
-rsa==4.7
+rsa==3.4.2
 rtv==1.27.0
 Scrapy==1.8.0
 semver==2.9.0
@@ -195,7 +195,7 @@ gpg==1.13.1
 gpiozero==1.5.1
 guizero==1.1.0
 haxor-news==0.4.3
-httplib2==0.18.0
+httplib2==0.19.0
 hyperlink==19.0.0
 idna==2.10
 incremental==17.5.0
@@ -251,7 +251,7 @@ python-vlc==3.0.10114
 pyzmq==18.1.0
 regex==2019.11.1
 requests==2.24.0
-rsa==4.7
+rsa==3.4.2
 sh==1.12.14
 six==1.15.0
 soupsieve==2.0.1