Optionally allow basic auth

This can be useful for setups of InfluxDB 1.8 without authentication when authentication is handled by a proxy instead.

influxdb_client/client/influxdb_client.py

@@ -3,7 +3,7 @@
 from __future__ import absolute_import
 
 import configparser
-import os
+import os, base64
 
 from influxdb_client import Configuration, ApiClient, HealthCheck, HealthService, Ready, ReadyService
 from influxdb_client.client.authorizations_api import AuthorizationsApi
@@ -66,6 +66,12 @@ def __init__(self, url, token, debug=None, timeout=10_000, enable_gzip=False, or
         auth_header_name = "Authorization"
         auth_header_value = "Token " + auth_token
 
+        # allow basic authentication for cases where InfluxDB (backwards 1.8 doesn't use auth but proxies perform basic auth)
+        auth_basic = kwargs.get('auth_basic', False)
+        if auth_basic:
+            auth_header_value = "Basic " + base64.b64encode(token.encode()).decode()
+
+
         retries = kwargs.get('retries', False)
 
         self.api_client = ApiClient(configuration=conf, header_name=auth_header_name,