Update __init__.py (#67)

Adding context.load_default_certs() to fix SSL failures

Author: Emory Penney

gpsoauth/__init__.py

@@ -77,6 +77,7 @@ def init_poolmanager(self, *args: Any, **kwargs: Any) -> None:
             context.set_ciphers(SSL_DEFAULT_CIPHERS)
         context.verify_mode = ssl.CERT_REQUIRED
         context.options &= ~ssl.OP_NO_TICKET  # pylint: disable=E1101
+        context.load_default_certs()
         self.poolmanager = PoolManager(*args, ssl_context=context, **kwargs)