Remove some unused dependencies

Upgrade to the latest tokio-rustls

Update ct-logs requirement from 0.4 to 0.5

Update webpki-roots requirement from 0.15 to 0.16

Update webpki requirement from 0.18.1 to 0.19.0

Updates the requirements on [webpki-roots](https://github.com/ctz/webpki-roots) to permit the la...

Updates the requirements on [ct-logs](https://github.com/ctz/ct-logs) to permit the latest versi...

Updates the requirements on [webpki](https://github.com/briansmith/webpki) to permit the latest ...

Forward read_buf and write_buf for MaybeHttpsStream

Add hyper support for ALPN h2

examples: wait for all tasks

allow create HttpsConnector from Arc<ClientConfig>

This properly waits for all asynchrounous tasks to complete before
completing.

Bumped rustls and tokio-rustls versions

example: clean and add error handling

This removes all unwraps and excepts from both client and server
examples, as well as adding few...

examples/server: warn when aborting on connection errors

As the example server is used for CI purposes, it is convenient that
it aborts on any client err...

travis: add a clippy pass

connector: do not panic on wrong dnsname

src: update to hyper 0.12

This updates to hyper 0.12 and tokio-rustls 0.6, getting rid of
tokio-proto support.

Update to rustls 0.12

This is needed in order to fix some recent breakage in ring on nightly
builds.

Formatted with 0.3.4-nightly.

examples/server: fix warnings

lib: add rustdoc comments

connector: build from custom rustls ClientConfig

cargo: update depends and bump to 0.8.0

- bump webpki-roots, older webpki crates have been removed from crates.
- Fix multiple versions ...

cargo: update hyper to 0.11

This updates the library to use Hyper's new futures-based Connect trait.

Bump to the latest version of rustls and webpki-roots

For issue #7

Fix endless loop in read when there is io error in underlying_write.

When this happens we early exit from underlying_read so flag for eof
is never set. Because of thi...

Upgrade to Hyper 0.10