Merge branch 'develop'

* develop:
  fix requirements.txt
  migrate to google-auth from oauth2client
  update requirements.txt
  + [how it works] in README

README.md

@@ -3,3 +3,7 @@
 [![Build Status](https://travis-ci.org/b4tman/sync_ics2gcal.svg?branch=master)](https://travis-ci.org/b4tman/sync_ics2gcal)
 
 Python scripts for sync .ics file with Google calendar
+
+## How it works
+
+![How it works](how-it-works.png)

gcal_sync/gcal.py

@@ -1,10 +1,11 @@
-from apiclient import discovery
-import httplib2
 import logging
-from oauth2client import service_account
-from pytz import utc
 import sys
 
+import google.auth
+from google.oauth2 import service_account
+from googleapiclient import discovery
+from pytz import utc
+
 
 class GoogleCalendarService():
     """class for make google calendar service Resource
@@ -21,14 +22,12 @@ class GoogleCalendarService():
             service Resource
         """
 
-        scopes = 'https://www.googleapis.com/auth/calendar'
-        credentials = service_account.ServiceAccountCredentials.from_json_keyfile_name(
-            service_account_file, scopes=scopes)
-        http = credentials.authorize(httplib2.Http())
-        service = discovery.build('calendar', 'v3', http=http)
+        scopes = ['https://www.googleapis.com/auth/calendar']
+        credentials = service_account.Credentials.from_service_account_file(service_account_file)
+        scoped_credentials = credentials.with_scopes(scopes)
+        service = discovery.build('calendar', 'v3', credentials=scoped_credentials)
         return service
 
-
 def select_event_key(event):
     """select event key for logging
     

requirements.txt

@@ -1,4 +1,5 @@
-google-api-python-client==1.6.6
-icalendar==4.0.1
-pytz==2018.3
-PyYAML==3.12
+google-auth==1.5.0
+google-api-python-client==1.7.3
+icalendar==4.0.2
+pytz==2018.5
+PyYAML==3.13