Bump lxml from 3.8.0 to 4.6.2 in /070

Bumps [lxml](https://github.com/lxml/lxml) from 3.8.0 to 4.6.2.
- [Release notes](https://github.com/lxml/lxml/releases)
- [Changelog](https://github.com/lxml/lxml/blob/master/CHANGES.txt)
- [Commits](lxml/lxml@lxml-3.8.0...lxml-4.6.2)

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

Author: dependabot[bot]

070/requirements.txt

@@ -1,4 +1,4 @@
 html5lib==0.999999999
 ipykernel==4.6.1
-lxml==3.8.0
+lxml==4.6.2
 pandas==0.20.2