Update ipython requirement from ~=7.18.1 to ~=7.19.0 (#31)

Updates the requirements on [ipython](https://github.com/ipython/ipython) to permit the latest version.
- [Release notes](https://github.com/ipython/ipython/releases)
- [Commits](ipython/ipython@7.18.1...7.19.0)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements-dev.txt

@@ -10,7 +10,7 @@
 coverage ~=5.3
 flake8 ~=3.8.4
 pytest ~=6.1.0
-ipython ~=7.18.1
+ipython ~=7.19.0
 numpydoc ~=1.1.0
 sphinx ~=3.3.1
 sphinx-copybutton ~=0.3.1