Add xdoctest to the develop dependencies

poetry.lock

@@ -965,10 +965,28 @@ category = "main"
 optional = false
 python-versions = "*"
 
+[[package]]
+name = "xdoctest"
+version = "0.15.0"
+description = "A rewrite of the builtin doctest module"
+category = "dev"
+optional = false
+python-versions = "*"
+
+[package.dependencies]
+six = "*"
+
+[package.extras]
+all = ["six", "pytest", "pytest-cov", "codecov", "scikit-build", "cmake", "ninja", "pybind11", "pygments", "colorama", "nbformat", "nbconvert", "jupyter-client", "ipython", "ipykernel"]
+colors = ["pygments", "colorama"]
+jupyter = ["nbformat", "nbconvert", "jupyter-client", "ipython", "ipykernel"]
+optional = ["pygments", "colorama", "nbformat", "nbconvert", "jupyter-client", "ipython", "ipykernel"]
+tests = ["pytest", "pytest-cov", "codecov", "scikit-build", "cmake", "ninja", "pybind11", "nbformat", "nbconvert", "jupyter-client", "ipython", "ipykernel"]
+
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.8"
-content-hash = "abc30be36880f8b203c72895f70f906ef451fca6b4e5113891c9487bc95e02e5"
+content-hash = "0483228a1bbf92c52f5045db05de80b951dbd7302db756ca6f65cd56b482b814"
 
 [metadata.files]
 appdirs = [
@@ -1487,3 +1505,7 @@ webencodings = [
     {file = "webencodings-0.5.1-py2.py3-none-any.whl", hash = "sha256:a0af1213f3c2226497a97e2b3aa01a7e4bee4f403f95be16fc9acd2947514a78"},
     {file = "webencodings-0.5.1.tar.gz", hash = "sha256:b36a1c245f2d304965eb4e0a82848379241dc04b865afcc4aab16748587e1923"},
 ]
+xdoctest = [
+    {file = "xdoctest-0.15.0-py2.py3-none-any.whl", hash = "sha256:695ea04303a48cbb319709270d43f7bae7f3de3701aec73f09d90a216499992e"},
+    {file = "xdoctest-0.15.0.tar.gz", hash = "sha256:7f0a184d403b69b166ebec1aadb13c98c96c59101e974ae2e4db4c3a803ec371"},
+]

pyproject.toml

@@ -21,6 +21,9 @@ numpy = "^1.19.2"
 nox = "^2020.8.22"
 pre-commit = "^2.7.1"
 
+# Testing
+xdoctest = "^0.15.0"
+
 # Live coding during presentation mode
 jupyter-contrib-nbextensions = "^0.5.1"
 rise = "^5.6.1"