Fix setup script

Author: gartens

setup.py

@@ -2,13 +2,12 @@
 
 from setuptools import setup
 
-version = os.getenv('version', '0.0').split('.')
-if len(version) != 2:
-    raise Exception('Invalid version format')
+version = os.getenv('version', '0.0')
+major, minor = version.split('.')
 
 with open('org/polypheny/prism/version.py', 'w') as f:
-    f.write(f'MAJOR_VERSION = {version[0]}\n')
-    f.write(f'MINOR_VERSION = {version[1]}\n')
+    f.write(f'MAJOR_VERSION = {major}\n')
+    f.write(f'MINOR_VERSION = {minor}\n')
 
 setup(name='polyphenyprism',
       version=version,