Add testing requirements and banner to README

* doc: add testing to README

* feat(marketing): add logo assets to repo and README

README.md

@@ -1,3 +1,5 @@
+![boringtun logo banner](./banner.png)
+
 # boringtun
 
 **boringtun** is an implementation of the [WireGuard<sup>®</sup>](https://www.wireguard.com/) protocol designed for portability and speed.
@@ -14,6 +16,13 @@ The project consists of two parts:
 
 By default the executable is placed in the `./target/release` folder. You can copy it to a desired location manually, or install it using `cargo install --bin boringtun --path .`.
 
+## Testing
+
+Testing this project has a few requirements:
+
+- `sudo`: required to create tunnels. When you run `cargo test` you'll be prompted for your password.
+- Docker: you can install it [here](https://www.docker.com/get-started). If you are on Ubuntu/Debian you can run `apt-get install docker.io`.
+
 ### Running
 
 As per the specification, to start a tunnel use:
@@ -68,4 +77,4 @@ The library exposes a set of Java Native Interface bindings, those are defined i
 The project is licensed under the [3-Clause BSD License](https://opensource.org/licenses/BSD-3-Clause).
 
 ---
-<sub><sub><sub><sub>WireGuard is a registered trademark of Jason A. Donenfeld. boringtun is not sponsored or endorsed by Jason A. Donenfeld.</sub></sub></sub></sub>
+<sub><sub><sub><sub>WireGuard is a registered trademark of Jason A. Donenfeld. boringtun is not sponsored or endorsed by Jason A. Donenfeld.</sub></sub></sub></sub>