Update notification has wrong URL

[shouptech]

The upgrade notification displays a URL like this:
https://github.com/kubernetes/minikube/releases/tag/v/1.3.1
The correct URL should be:
https://github.com/kubernetes/minikube/releases/tag/v1.3.1

There's an extra slash between v and 1.3

The exact command to reproduce the issue:
This happens when my shell (zsh) loads the tab completion.

The full output of the command that failed:

minikube 1.3.1 is available! Download it: https://github.com/kubernetes/minikube/releases/tag/v/1.3.1

The output of the minikube logs command:

N/A

The operating system version:
Linux <> 5.0.0-21-generic #22+system76-Ubuntu SMP Tue Jul 16 19:57:52 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

[tstromberg]

Hum. How on earth did that happen?

Spoiler alert: I broke it in a refactor:
3d7c657

[tstromberg]

Thank you for opening an issue rather than just letting this bug sit and aggravate future users =)