NoClassDefFoundError: Failed resolution of: Lokhttp3/internal/Platform

I guess, the problem is here:

compile 'com.squareup.okhttp3:logging-interceptor:3.3.0'
compile 'com.squareup.okhttp3:okhttp:3.4.1'

Try to make that:

compile 'com.squareup.okhttp3:logging-interceptor:3.4.1'
compile 'com.squareup.okhttp3:okhttp:3.4.1'