Merge pull request readium#375 from readium/2.2.0-beta.1

2.2.0-beta.1

Bump version to 2.2.0, build 25

Merge pull request readium#275 from readium/develop

V2.1.0-beta.4

Merge pull request readium#272 from readium/fixes/debug

wrap timber logs to only show in debug builds and source formatting

Merge pull request readium#230 from readium/fixes/duplicate_publications

Fixes/duplicate publications

tagging play-store beta

Merge pull request readium#213 from readium/develop

V2.0.0-beta.6

Merge pull request readium#179 from readium/develop

version bump