check and install go if not there in main.go about pushup

[gedw99]

It works on ALL OS. Its got nothing to do with Brew :)

gobrew install 1.19.0
==> [Info] Downloading version: 1.19 
==> [Info] Downloading from: https://go.dev/dl/go1.19.darwin-amd64.tar.gz 
==> [Info] Downloading to: /Users/apple/.gobrew/downloads 
Downloading 100% |█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| (144/144 MB, 7.9 MB/s)         
==> [Info] Extracting from: /Users/apple/.gobrew/downloads/go1.19.darwin-amd64.tar.gz 
==> [Info] Extracting to: /Users/apple/.gobrew/versions/1.19 
==> [Success] Untar to /Users/apple/.gobrew/versions/1.19
==> [Success] Downloaded version: 1.19
apple@x-MacBook-Pro-2 pushup % gobrew ls            
1.19
1.20.4*
1.20.5

current: 1.20.4