Add a homebrew formula

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

Formula/kubectx.rb

@@ -0,0 +1,24 @@
+class Kubectx < Formula
+    desc "Tool that can switch between kubectl contexts easily and create aliases"
+    homepage "https://github.com/ahmetb/kubectx"
+    url "https://github.com/ahmetb/kubectx/archive/v0.1.zip"
+    sha256 "3d014027e38c476164638b2138f190c43fd65a22ec50035c36926555233247c0"
+
+    bottle :unneeded
+
+    def install
+        bin.install "kubectx"
+        bash_completion.install "completion/kubectx.bash" => "kubectx"
+    end
+
+    test do
+        system "kubectx", "--help"
+    end
+
+    def caveats; <<-EOS.undent
+      To install zsh completion, add this to your .zshrc:
+
+        [ -f /usr/local/etc/bash_completion.d/kubectx ] && source /usr/local/etc/bash_completion.d/kubectx
+      EOS
+    end
+end