Bump ipython from 7.14.0 to 7.15.0 in /src/requirements (#545)

Bumps [ipython](https://github.com/ipython/ipython) from 7.14.0 to 7.15.0.
- [Release notes](https://github.com/ipython/ipython/releases)
- [Commits](https://github.com/ipython/ipython/compare/7.14.0...7.15.0)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

src/requirements/production.txt

@@ -20,7 +20,7 @@ future==0.18.2
 graphene-django==2.10.0
 html5lib==1.0.1
 icalendar==4.0.6
-ipython==7.14.0
+ipython==7.15.0
 irc3==1.1.5
 lxml==4.5.0
 olefile==0.46