replace license in setup.cfg

setup.cfg

@@ -3,7 +3,7 @@ name = teach_auto
 version = attr: teach_auto.__version__
 author = Cyril Matthey-Doret
 author_email = cyril.matthey-doret@epfl.ch
-license = GPLv3
+license = MIT
 description = Utilities to automate classroom management with Gitlab and Renku.
 keywords = automation, git, gitlab, teaching
 url = https://renkulab.io/gitlab/learn-renku/teaching-on-renku/advanced-teaching-automation
@@ -13,4 +13,4 @@ classifiers =
     Programming Language :: Python :: 3.10
     Intended Audience :: Education
     Topic :: Software Development :: Version Control :: Git
-    License :: OSI Approved :: GNU General Public License v3 (GPLv3)
\ No newline at end of file
+    License :: OSI Approved :: MIT License