Template packagename in oldestdeps tox command (#52)

* Fix oldestdeps in tox

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

{{ cookiecutter.package_name }}/tox.ini

@@ -20,7 +20,7 @@ description =
     oldestdeps: with the oldest supported version of key dependencies
 
 # Pass through the following environment variables which may be needed for the CI
-pass_env = 
+pass_env =
     HOME
     WINDIR
     LC_ALL
@@ -30,7 +30,7 @@ pass_env =
     TRAVIS
 
 # Suppress display of matplotlib plots generated during docs build
-set_env = 
+set_env =
     MPLBACKEND=agg
 
 # Run the tests in a temporary directory to make sure that we don't import
@@ -46,7 +46,7 @@ extras =
     test
 
 commands_pre =
-    oldestdeps: minimum_dependencies packagename --filename requirements-min.txt
+    oldestdeps: minimum_dependencies {{ cookiecutter.module_name }} --filename requirements-min.txt
     oldestdeps: pip install -r requirements-min.txt
     pip freeze