More ReST fixes
Use cases doc section. Closes #239
Protect dict access. Closes #246
Remove repeated section
BrowserID support. Closes #228
v0.6.3
Add Instagram support
Merge pull request #247 from r4vi/instagram

Add Instagram support
Instagram doc and small code styling. Refs #247
Doc fix
Change Yahoo OpenID URL. Closes #249
v0.6.4
Raise exceptions setting. Closes #248.
Styling
Fixed formatting of README file to correctly render as rST on PyPI.
Merge pull request #250 from jezdez/rst-bugfix

Fixed formatting of README file to correctly render as rST on PyPI.
Improve and fix partial pipeline arguments management. Closes #251
v0.6.5
Save model instances into session in a easy format to retrieve it later. Refs #251
Overrideable user check for get_username pipeline. Refs #253