throughput measurements for android

[trevj]

We need some idea of throughput on mobile. What's the throughput in ideal situations? How does latency affect this?

This PR includes a bunch of throughput measurements for a beefy workstation: https://github.com/uProxy/uproxy-docker/pull/96

Mobile's different. I think we're going to want to:

• setup a cloud server
• get some devices, e.g. Nexus 5X
• note the latency between our device(s) and the server
• time how long it takes to download some large file via the proxy