v2.0.0

• Add django_util (#332)
• Avoid OAuth2Credentials id_token going out of sync after a token refresh (#337)
• Move to a contrib sub-package code not considered a core part of the library (#346, #353, #370, #375, #376, #382)
• Add token_expiry to devshell credentials (#372)
• Move Storage locking into a base class (#379)
• Added dictionary storage (#380)
• Added to_json and from_json methods to all Credentials classes (#385)
• Fall back to read-only credentials on EACCES errors (#389)
• Coalesced the two ServiceAccountCredentials classes (#395, #396, #397, #398, #400)

Special Note About ServiceAccountCredentials:

For JSON keys, you can create a credential via

from oauth2client.service_account import ServiceAccountCredentials
credentials = ServiceAccountCredentials.from_json_keyfile_name(
    key_file_name, scopes=[...])

You can still rely on

from oauth2client.client import GoogleCredentials
credentials = GoogleCredentials.get_application_default()

returning these credentials when you set the GOOGLE_APPLICATION_CREDENTIALS environment variable.

For .p12 keys, construct via

credentials = ServiceAccountCredentials.from_p12_keyfil(
    service_account_email, key_file_name, scopes=[...])

though we urge you to use JSON keys (rather than .p12 keys) if you can. This is equivalent to the previous method

# PRE-oauth2client 2.0.0 EXAMPLE CODE!
from oauth2client.client import SignedJwtAssertionCredentials
with open(key_file_name, 'rb') as key_file:
    private_key = key_file.read()
credentials = SignedJwtAssertionCredentials(
    service_account_email, private_key, scope=[...])