defer resolving of env vars until API call (#8)

Author: cesarferradas

heron/__init__.py

@@ -1,9 +1,7 @@
-import os
-
 _base_url = "https://app.herondata.io/api"
 
-basic_auth_username = os.getenv("HERON_USERNAME")
-basic_auth_password = os.getenv("HERON_PASSWORD")
+basic_auth_username = None
+basic_auth_password = None
 provider = None
 
 from .category import Category  # noqa

heron/base.py

@@ -1,3 +1,4 @@
+import os
 from json.decoder import JSONDecodeError
 
 import requests
@@ -36,8 +37,8 @@ def do_request(cls, method, path=None, json=None, retry=False, **params):
             headers={"Content-Type": "application/json"},
             json=json,
             auth=requests.auth.HTTPBasicAuth(
-                basic_auth_username or "",
-                basic_auth_password or "",
+                basic_auth_username or os.getenv("HERON_USERNAME", ""),
+                basic_auth_password or os.getenv("HERON_PASSWORD", ""),
             ),
             **kwargs,
         )