Update setup.py

Author: filland

setup.py

@@ -12,7 +12,7 @@
     url='https://github.com/reportportal/client-Python',
     download_url=('https://github.com/reportportal/client-Python/'
                   'tarball/%s' % __version__),
-    license='GNU General Public License v3',
+    license='Apache 2.0.',
     keywords=['testing', 'reporting', 'reportportal'],
     classifiers=[],
     install_requires=['requests>=2.4.2', 'six'],