Add k3s to dependency check

Signed-off-by: Morgan Tocker <tocker@gmail.com>

tools/dependency_check.sh

@@ -24,6 +24,6 @@ function fail() {
 # These binaries are required to 'make test'
 # mysqld might be in /usr/sbin which will not be in the default PATH
 PATH="/usr/sbin:$PATH"
-for binary in mysqld consul etcd etcdctl zksrv.sh javadoc mvn ant curl wget zip unzip; do
+for binary in k3s mysqld consul etcd etcdctl zksrv.sh javadoc mvn ant curl wget zip unzip; do
   command -v "$binary" > /dev/null || fail "${binary} is not installed in PATH. See https://vitess.io/contributing/build-from-source for install instructions."
 done;