It's very weird, with build plugin 3.0.0-beta4 almost all dependencies must be repeated in the "androidTest" variant.
If I check dependnecies tries the dependenci in app module looks like this
+--- com.flurry.android:analytics:6.3.1 -> 6.6.0
and in the appTest module always just like this (the same dependency, the "->" is always missing for all the dependencies in the dependency tree)
So it looks that in the androidTest dependencies doesn't work the latest version resolving mechanism like normally should work.