Fix the build order so that the plugin can target the latest instrumentation library

[mannodermaus]

Issues like #344 were already fixed in the latest instrumentation library, but the latest plugin shipped with an older release. This is wrong and made even more confusing by the readme. Since the plugin references the instrumentation library, but the instrumentation library doesn't directly reference the plugin, we may be able to swap the order in which they are released: Instrumentation first, plugin second.