Update project and dependencies

[friederbluemle]

A bunch of dependency and project updates/cleanups.

Latest versions of Dagger (2.17), Gradle wrapper (4.10.2), and Android Gradle plugin (3.2.0).

https://android-developers.googleblog.com/2018/09/android-studio-32.html

Closes #12, closes #15

_{^{Once approved, please use a normal GitHub merge (i.e. NO rebase/squash merge) to integrate the commit(s) from the branch of this pull request. The changes are broken up into meaningful, atomic commits, and my branch should already be up-to-date with the latest target branch. If it isn't, or if you'd like me to combine something, please let me know, and I will make the necessary updates as soon as possible. Thank you!}}

[friederbluemle]

Updated to the latest versions again. @iammert Could you take a look please?