v3.0.5

Add constant for resource.

Bump php-jwt to 5.0.0

Bump php-jwt to 5.0.0
Fix exception error message in Sainsburys\Guzzle\Oauth2\AccessToken

Allow optional client secret

Merge pull request #12 from Tobion/fix-optional-secret

client_secret is optional in all grant types

Allowing updated version of Firebase JWT

v3.0.2

Update composer.lock

Add a couple of config constants

Merge pull request #6 from chx/patch-1

Introduce config constants

v3.0.0

Release 3.0.0

v2.2.0

Release 2.2.0

v1.1.0: [STB-71] [ID-27] Change namespace to Sainsbury's

Freeze guzzle/guzzle to 3.x
Add composer.lock
Bring in .gitignore

Signed-off-by: Daniel Macedo <admacedo@gmail.com>