[chore]add POST support to api
Merge pull request #53 from peterzd/api_send_support

[chore]add POST support to api
[feature]add authentication_token to users for API token
[feature]introduce devise authentication for API

Note: every request should add `access_token` params if request for some
user-sensitive resources
[chore]user concern to refactor v1 API
[feature]endpoint can register user
[chore]user can sign in via API
Merge pull request #54 from peterzd/api_authenticate

Api authenticate
[feature]endpoint can upload picture
[feature]add users/profile, users/my_cards api

Note: in api, to present Entity, use `with`, in Entities, use `using`
[feature]user can update his own profile
Merge pull request #55 from peterzd/api_upload_picture

Api upload picture
[feature]save image will update card's updated_at time
[feature]likes a photo will touch card
[feature]user joins a card will touch the card
[feature]user comments on photo will touch photo's card
[chore]update photo's album to make tests pass
[feature]auto add the creator to the card's followers
[chore]fix tests to make it pass
[feature]show user's profile cards based on updated_at desc

Note: each social feed will update the card's updated_at value