The versions i'm using are
implementation 'io.reactivex.rxjava2:rxjava:2.2.4'
implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'
implementation 'com.jakewharton.rxbinding2:rxbinding:2.0.0'
implementation 'com.jakewharton.retrofit:retrofit2-rxjava2-adapter:1.0.0'
implementation 'android.arch.persistence.room:runtime:2.1.0-alpha04'
kapt 'android.arch.persistence.room:compiler:2.1.0-alpha04'
implementation 'android.arch.persistence.room:rxjava2:2.1.0-alpha04'
and the Dao is
@Insert(onConflict = OnConflictStrategy.REPLACE)
fun insertStore(stores: Stores): Completable