minikube: disable shell autocompletion; causes impurities.

Apparently the the generation of auto completion files depends on a
network connection. My `nix-build --pure` failed because of this.
Disabled autocompletion for now, given that minikube prints out lots of
documentaton if you provide partial commands.

pkgs/applications/networking/cluster/minikube/default.nix

@@ -30,9 +30,6 @@ stdenv.mkDerivation rec {
   installPhase = ''
     cp $src $out/bin/${pname}
     chmod +x $out/bin/${pname}
-
-    mkdir -p $out/share/bash-completion/completions/
-    HOME=$(pwd) $out/bin/minikube completion bash > $out/share/bash-completion/completions/minikube
   '';
 
   meta = with stdenv.lib; {