## 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
```py
from oauth2client.service_account import ServiceAccountCredentials
credentials = ServiceAccountCredentials.from_json_keyfile_name(
key_file_name, scopes=[...])
```
You can still rely on
```py
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
```py
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
```py
# 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=[...])
```