Add support for s390x

[vmorris]

Summary
s390x is not supported as as installation target.

[install_ibmcloud] Downloading and installing IBM Cloud 'ibmcloud' CLI from: https://clis.cloud.ibm.com/install/linux

Steps to reproduce
(include tooling version, platform, etc)

1. curl -sL https://ibm.biz/idt-installer | bash

ubuntu@zs93c8:~$ curl -sL https://ibm.biz/idt-installer | bash
[main] --==[ IBM Cloud Developer Tools for Linux/MacOS - Installer, v1.2.3 ]==--
[install] Starting Update...
[install] Note: You may be prompted for your 'sudo' password during install.
[install_deps_with_apt_get] Checking for and updating 'apt-get' support on Linux
Hit:1 http://ports.ubuntu.com/ubuntu-ports disco InRelease
 ... OUTPUT REMOVED ...
[install_deps_with_apt_get] Installing/updating external dependency: curl
[install_deps_with_apt_get] Installing/updating external dependency: git
[install_docker] Installing/updating external dependency: docker
Client:
 Version:           18.06.1-ce
 API version:       1.38
 Go version:        go1.10.3
 Git commit:        e68fc7a
 Built:             Tue Aug 21 17:24:27 2018
 OS/Arch:           linux/s390x
 Experimental:      false

Server:
 Engine:
  Version:          18.06.1-ce
  API version:      1.38 (minimum version 1.12)
  Go version:       go1.10.3
  Git commit:       e68fc7a
  Built:            Tue Aug 21 17:23:26 2018
  OS/Arch:          linux/s390x
  Experimental:     false
[install_deps_with_apt_get] Installing/updating external dependency: kubectl
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   278  100   278    0     0   1664      0 --:--:-- --:--:-- --:--:--  1654
######################################################################## 100.0%
[install_deps_with_apt_get] Please review any setup requirements for 'kubectl' from: https://kubernetes.io/docs/tasks/tools/install-kubectl/
[install_deps_with_apt_get] Installing/updating external dependency: helm
No prebuilt binary for linux-s390x.
To build from source, go to https://github.com/helm/helm
Failed to install helm
	For support, go to https://github.com/helm/helm.
[install_deps_with_apt_get] Please review any setup requirements for 'helm' from: https://github.com/kubernetes/helm/blob/master/docs/install.md
[install_ibmcloud] Installing IBM Cloud 'ibmcloud' CLI for platform 'Linux'...
[install_ibmcloud] Downloading and installing IBM Cloud 'ibmcloud' CLI from: https://clis.cloud.ibm.com/install/linux
Unsupported Linux architecture: s390x. Quit installation.
[install_ibmcloud] IBM Cloud 'ibmcloud' CLI install finished.
[install_ibmcloud] Running 'ibmcloud --version'...
main: line 312: ibmcloud: command not found
[install_plugins] Installing/updating IBM Cloud CLI plugins...
[install_plugins] Checking status of plugin: cloud-functions
main: line 329: ibmcloud: command not found
[install_plugins] Installing plugin 'cloud-functions'
main: line 332: ibmcloud: command not found
[install_plugins] Checking status of plugin: cloud-object-storage
main: line 329: ibmcloud: command not found
[install_plugins] Installing plugin 'cloud-object-storage'
main: line 332: ibmcloud: command not found
[install_plugins] Checking status of plugin: container-registry
main: line 329: ibmcloud: command not found
[install_plugins] Installing plugin 'container-registry'
main: line 332: ibmcloud: command not found
[install_plugins] Checking status of plugin: container-service
main: line 329: ibmcloud: command not found
[install_plugins] Installing plugin 'container-service'
main: line 332: ibmcloud: command not found
[install_plugins] Checking status of plugin: dev
main: line 329: ibmcloud: command not found
[install_plugins] Installing plugin 'dev'
main: line 332: ibmcloud: command not found
[install_plugins] Running 'ibmcloud plugin list'...
main: line 339: ibmcloud: command not found
[install_plugins] Finished installing/updating plugins
[env_setup] WARN: Please restart your shell to enable 'ic' alias for ibmcloud!
[install] Install finished.
[main] --==[ Total time: 17 seconds ]==--

Operating System
Linux, Ubuntu 19.04 (Disco), s390x

---

Development "done" checklist

• Test case to verify
• Public Documentation updated
• Change added to "release notes" as appropropriate
• Notification to stakeholders (OM, other squads, etc)

[sandeep-at-ibm]

@vmorris please follow progress on

• Add support for Linux on s390x architecture (IBM Z/LinuxONE platform) ibm-cloud-cli-release#113 (comment)
• https://github.ibm.com/Bluemix/bluemix-cli/issues/3085

Current status:

• the s390x pipeline for Staging is ready
• Ross has added the tke plugin
• Waiting for dbaas and hpvs plugins to be added
• Waiting for publish to prod