Keeps connect on 2.x

connect 3.0 changed some stuff and removed middlewares. Keep it at 2.x
until a better port can be done
Adds support for chain/CA certificates

Some certificates need intermediate/root/ca certificates to work
correctly.
This adds support for a 'chain' option on the `config.json` ssl
configuration to allow for such intermediate/root/ca stuff.
Merge pull request #5 from coredump/master

Support for CA/intermediate certs and pinning connect version