Update install-linux.sh (#201)

Fix typos

install-linux.sh

@@ -7,7 +7,7 @@ sudo sh -c 'echo "deb [arch=amd64] https://packages.microsoft.com/repos/microsof
 sudo apt-get -qq update
 sudo apt-get install -y dotnet-sdk-2.1
 
-echo 'Installing kubecl'
+echo 'Installing kubectl'
 curl -Lo kubectl https://storage.googleapis.com/kubernetes-release/release/v1.9.0/bin/linux/amd64/kubectl
 chmod +x kubectl
 sudo mv kubectl /usr/local/bin/