Elfeed v1.2.0

Relevant for users

• Added an action to mark an entry as unread in entry scene
• Added the possibility to select multiple entries and mark them as read/unread in entries scene
• Disabled temporarily "swipeable action (mark as read/unread)" for entries due to a bug in RN

Relevant for developers

• Cleaned unnecessary code
• Simplified layout code
• Fixed layout issues related to the upgrade of RN v0.39
• Updated open-entry-browser fn to be pure
• Updated ReactNative version to v0.39.2
• Updated project clojure/script dependencies
• Updated IP in dev environment to work properly with Figwheel and Genymotion emulator