Ensure that $(go env GPATH)/bin is in PATH before running protoc, as it
looks for plugins (such as protoc-gen-go) there.

Signed-off-by: Sergei Trofimov <sergei.trofimov@arm.com>

Keycloak's logging lib expects flags to be parsed, otherwise it
complains, so we're parsing them. The problem is that if we actually
have any flags specified, parsing will fail, as the lib doesn't know
about Veraison flags, so clear os.Args of flags before calling
flags.Parse().

This is fine as KeycloakAuthorizer.Init(), where the call occurs, is
invoked well after the service command line has already been processed,
so os.Args won't be ever be used from then on.

This does mean that we can no longer pass configuration for Keycloak
logging lib on the command line, which was theoretically possible
before. However we've literally never do this, it's completely
undocumented, and may potentially cause conflicts with Veraison's own
logging. So this fixes that as well.

Signed-off-by: Sergei Trofimov <sergei.trofimov@arm.com>

Add "ca-cert" config for "keycloak" auth backend. This allows specifying
and additional CA cert to be used when connecting to the Keycloak
authentication server. This removes the need for the cert to installed
in the system.

Signed-off-by: Sergei Trofimov <sergei.trofimov@arm.com>

Add scripts to build, deploy, and run Veraison natively on the host
system.

While this is primarily a "local" deployment, i.e. intended to be run
locally for development/testing/demo purposes (similar to the existing
docker deployment), this is also intended to provide a basis for future
production deployments as well.

- Boostrap scripts are provided to ensure suitable build environment.
- Deployment steps can be executed separately, to e.g. omit client
  installation.
- Commands for generating certificates and the signing key are included
  in the frontend (though the use of pre-created "example" certs and
  keys is still possible).
- While the quick deployment is user-specific, system-level systemd
  units are also included, so its possible to, e.g. deploy into /opt
  and then install system units to provide a deployment that runs
  independent of user login. (note: a full system deployment would
  require dedicated user configuration, symlinking executables into
  /usr/local/bin, etc... That currently doesn't exist.)

In addition to the deployment code itself, this commit makes the
following amendments:

- end-to-end flow is updated to work with the native deployment, as well
  as docker via an alternate script, end-to-end-native. The existing
  script is renamed to end-to-end-docker.
- The top-level README.md is updated with native deployment
  instructions.
- Fixed line breaks inside top-level README.md to conform to the 79
  column standard.
- Fixed admonitions inside top-level REAME.md to use the GitHub extended
  syntax.

Signed-off-by: Sergei Trofimov <sergei.trofimov@arm.com>

Signed-off-by: Thomas Fossati <thomas.fossati@linaro.org>
Co-authored-by: Sergei Trofimov <sergei.trofimov@arm.com>

Signed-off-by: Thomas Fossati <thomas.fossati@linaro.org>
Co-authored-by: Sergei Trofimov <sergei.trofimov@arm.com>