Add etcd CLI to arkade

[klutchell]

Description

Add etcd CLI to arkade

Motivation and Context

Existing install process is clunky.

Before (from here and here)

ETCD_VERSION="v3.5.5"
ETCD_URL="https://github.com/etcd-io/etcd/releases/download/${ETCD_VERSION}/etcd-${ETCD_VERSION}-linux-amd64.tar.gz"
curl -sL ${ETCD_URL} | sudo tar -zxv --strip-components=1 -C /usr/local/bin

After

arkade get etcd

Fixes: #945

• I have raised an issue to propose this change, which has been given a label of design/approved by a maintainer (required)

How Has This Been Tested?

Unit tests, plus test tool output:

+ ./arkade get etcd --arch arm64 --os darwin --quiet
+ file /Users/kyle/.arkade/bin/etcd
/Users/kyle/.arkade/bin/etcd: Mach-O 64-bit arm64 executable, flags:<|DYLDLINK|PIE>
+ rm /Users/kyle/.arkade/bin/etcd
+ echo

+ ./arkade get etcd --arch x86_64 --os darwin --quiet
+ file /Users/kyle/.arkade/bin/etcd
/Users/kyle/.arkade/bin/etcd: Mach-O 64-bit x86_64 executable
+ rm /Users/kyle/.arkade/bin/etcd
+ echo

+ ./arkade get etcd --arch x86_64 --os linux --quiet
+ file /Users/kyle/.arkade/bin/etcd
/Users/kyle/.arkade/bin/etcd: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, Go BuildID=GyARklZhf9hi1aDRnamg/iBdV6hB-xGaEhWj0UVLe/sHhb4i0nu2-DUWKGC0Yw/4Y_A_aeQheHQIcJhyyC2, stripped
+ rm /Users/kyle/.arkade/bin/etcd
+ echo

+ ./arkade get etcd --arch aarch64 --os linux --quiet
+ file /Users/kyle/.arkade/bin/etcd
/Users/kyle/.arkade/bin/etcd: ELF 64-bit LSB executable, ARM aarch64, version 1 (SYSV), statically linked, Go BuildID=0_hf4eGUgeIZHwoJkukE/Cx-_IKMnyYRk24L0CmSi/o1qIZwTPv6-DoUGsXTHQ/i0Kjvgrkc76OspFXHhTs, stripped
+ rm /Users/kyle/.arkade/bin/etcd
+ echo

+ ./arkade get etcd --arch x86_64 --os mingw --quiet
+ file /Users/kyle/.arkade/bin/etcd.exe
/Users/kyle/.arkade/bin/etcd.exe: PE32+ executable (console) x86-64 (stripped to external PDB), for MS Windows, 6 sections
+ rm /Users/kyle/.arkade/bin/etcd.exe
+ echo

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Documentation

• I have updated the list of tools in README.md if (required) with ./arkade get --format markdown
• I have updated the list of apps in README.md if (required) with ./arkade install --help

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s

• I have tested this on arm, or have added code to prevent deployment

[alexellis]

Looks like the tests are failing for the PR

[Jasstkn]

LGTM.

[alexellis]

Thanks for the review @Jasstkn I'll get this merged. Thanks also @klutchell

[alexellis]

https://github.com/alexellis/arkade/releases/tag/0.9.26