ioutil.ReadAll will delete in future

Signed-off-by: 流雨声 <212724256@qq.com>

This commits updates version endpoint to use ProviderInfo and VersionInfo structs from
faas-provider.GatewayInfo now uses ProviderInfo and VersionInfo structs. GatewayInfo is
left within gateway. Consumer of this endpoint should use typed struct GatewayInfo to
parse response.

Signed-off-by: Vivek Singh <vivekkmr45@yahoo.in>

With this change /system/info endpoint is going to give
information about the platform architecture it is running on
(arm64, armhf, x86_64)

Signed-off-by: Ivana Yovcheva (VMware) <iyovcheva@vmware.com>

- Added Copyright in handlers where missing
- Renamed Project to Author(s) where needed

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

1. Use httptest.ResponseRecorder instead of custom implementation
StringResponseWriter.

2. Remove verbose log line in infohandler

Signed-off-by: Edward Wilde <ewilde@gmail.com>

Extend the health endpoint and add gateway version information

Resolves: #733
Signed-off-by: Edward Wilde <ewilde@gmail.com>