Bump ipython from 4.1.2 to 7.16.3

Bumps [ipython](https://github.com/ipython/ipython) from 4.1.2 to 7.16.3.
- [Release notes](https://github.com/ipython/ipython/releases)
- [Commits](ipython/ipython@4.1.2...7.16.3)

---
updated-dependencies:
- dependency-name: ipython
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -16,7 +16,7 @@ gnureadline==6.3.3
 gravatar==0.1
 html5lib==0.9999999
 idna==2.8
-ipython==4.1.2
+ipython==7.16.3
 ipython-genutils==0.1.0
 Jinja2>=2.10.1
 Markdown==2.6.6