Update jb install commands

Signed-off-by: Tamal Saha <[email protected]>

Author: tamalsaha

README.md

@@ -46,7 +46,7 @@ You can manually generate the alerts, dashboards and rules files, but first you
 must install some tools:
 
 ```
-$ go get github.com/jsonnet-bundler/jsonnet-bundler/cmd/jb
+$ go install github.com/jsonnet-bundler/jsonnet-bundler/cmd/jb@latest
 $ brew install jsonnet
 ```