Fix a couple of typos

Suggested-by: codespell & spellintian

Author: pabs3

pytest_rerunfailures.py

@@ -92,7 +92,7 @@ def _set_resultlog(config, resultlog):
 
 
 # making sure the options make sense
-# should run before / at the begining of pytest_cmdline_main
+# should run before / at the beginning of pytest_cmdline_main
 def check_options(config):
     val = config.getvalue
     if not val("collectonly"):

tox.ini

@@ -1,6 +1,6 @@
 # Tox (https://tox.readthedocs.io/en/latest/) is a tool for running tests
 # in multiple virtualenvs. This configuration file will run the
-# test suite on all supported python versions. To use it, "pip install tox"
+# test suite on all supported Python versions. To use it, "pip install tox"
 # and then run "tox" from this directory.
 
 [flake8]