Monkey-patch for grequests in pittapi __init__ (#197)

The grequests package monkey-patches ssl upon import, but this must be
done before all other imports or else we get a MonkeyPatchWarning or a
RecursionError.

References:
spyoungtech/grequests#150
gevent/gevent#1016

pittapi/__init__.py

@@ -17,6 +17,13 @@
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 """
 
+# grequests monkey-patches ssl, but this must be done before all other imports,
+# or else we may get a MonkeyPatchWarning or a RecursionError
+# See https://github.com/spyoungtech/grequests/issues/150 and https://github.com/gevent/gevent/issues/1016
+from gevent import monkey
+
+monkey.patch_all(thread=False, select=False)
+
 import urllib3
 from urllib3.exceptions import InsecureRequestWarning