Fix license.

Author: afoucret

setup.cfg

@@ -0,0 +1,5 @@
+[bdist_wheel]
+# This flag says that the code is written to work on both Python 2 and Python
+# 3. If at all possible, it is good practice to do this. If you cannot, you
+# will need to generate wheels for each Python version that you support.
+universal=1

setup.py

@@ -18,6 +18,7 @@
     name = 'elastic-site-search',
     version = about['VERSION'],
     description = 'Elastic Site Search API Client for Python',
+    license = 'Apache 2.0',
     long_description=long_description,
     long_description_content_type='text/markdown',
     author = 'Elastic',