Bump version
[feature] Extended image downloader

This commit ads a nicer API for image downloader,
making it easy to customize requests, like signed
requests.
[feature] Be able to store Facebook media URL

This commit provides the capability to cache Facebook
media URL, and expose it in the model.
Merge pull request #21 from SfietKonstantin/abstract-image-downloader

[feature] Extended image downloader
Merge pull request #22 from SfietKonstantin/url

Store media url