setup.py with correct download link

Author: chilango74

setup.py

@@ -8,7 +8,7 @@
     author='Sergey Kikevich',
     author_email='[email protected]',
     url='https://okama.io/',
-    download_url='https://github.com/user/reponame/archive/v_01.tar.gz',
+    download_url='https://github.com/mbk-dev/okama/archive/v0.8.tar.gz',
     keywords=['finance', 'investments', 'efficient frontier', 'python'],
     packages=['okama', 'tests'],
     package_data={'tests': ['*.csv']},