Add OpenSSL to the dex Docker container so wget can be used to query
HTTPS endpoint. This is a requirement for health checking when dex is
doing its own TLS termination.

This increased the image size from 20.37 MB to 20.92 MB (+550 KB).

Additionally add Ed and Rithu as maintainers.

api: add gRPC definition for version endpoint.

Small spelling fix.

README: fix links

README: add link on v2 and section on getting help

*: readme updates for v2

cmd/dex: only expand from env for storages and connectors

server: use seconds instead of nano seconds for expires_in and expiry

Documentation: add doc describing v2 changes

cmd/example-app: add a --debug flag

Bcrypt'd hashes have "$" characters in them. This means that #667
(accepting actually bcrypted values) combined with #627 (expanding
config with environment variables) broke the example config.

For now, allow storages and connectors to expand their configs from
the environment, but don't do this anywhere else.

cmd/dex: expose IDTokensValidFor and RotateKeysAfter server options in config

connector: accept base64 encoded CA and add convience open method

*: switch to github.com/ghodss/yaml for more consistent YAML parsing

ghodss/yaml converts from YAML to JSON before attempting to unmarshal.
This allows us to:

* Get the correct behavor when decoding base64'd []byte slices.
* Use *json.RawMessage.
* Not have to support extravagant YAML features.
* Let our structs use `json:` tags

*: travis tests and build scripts should use Go 1.7.3.

cmd/dex: add option for gRPC client auth CA.

*: don't error out if a username doesn't exist in the backing connector

api: add gRPC endpoints for creating, updating and deleting passwords

Instead of throwing a 500 error if a user enters an invalid name,
display the same text box as if the user had entered the wrong
password.

NOTE: An invalid username now returns much quicker than an invalid
password. Consider adding an arbitrary sleep in the future if we
care about masking which was invalid.

storage/sql: use isolation level "serializable" for transactions