We use `certificateAuthority(int)` to create certificates that can sign other certificates. The
int specifies how many intermediate certificates are allowed beneath it in the chain.

```java
HeldCertificate rootCertificate = new HeldCertificate.Builder()
    .certificateAuthority(1)
    .build();

HeldCertificate intermediateCertificate = new HeldCertificate.Builder()

HTTP is the way modern applications network. It’s how we exchange data & media. Doing HTTP
efficiently makes your stuff load faster and saves bandwidth.

OkHttp is an HTTP client that’s efficient by default:

 * HTTP/2 support allows all requests to the same host to share a socket.
 * Connection pooling reduces request latency (if HTTP/2 isn’t available).
 * Transparent GZIP shrinks download sizes.

OkCurl
======

_A curl for the next-generation web._

OkCurl is an OkHttp-backed curl clone which allows you to test OkHttp's HTTP engine (including