fix start.sh and stop.sh on ubuntu with zsh

moved to bash instead of sh
rewrite testing for existing file and directory so that hopefully it works on both Linux and MacOs

start.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 if [[ "$OSTYPE" == "darwin"* ]]; then
   OS='macosx-universal-64'
@@ -6,13 +6,15 @@ else
   OS='linux-x86-64'
 fi
 
-if ! ls sonar-application/target/sonarqube-*.zip &> /dev/null; then
+ls sonar-application/target/sonarqube-*.zip 1> /dev/null 2>&1
+if [ "$?" != "0" ]; then
   echo 'Sources are not built'
   ./build.sh
 fi
 
 cd sonar-application/target/
-if ! ls sonarqube-*/bin/$OS/sonar.sh &> /dev/null; then
+ls sonarqube-*/bin/$OS/sonar.sh 1> /dev/null 2>&1
+if [ "$?" != "0" ]; then
   unzip sonarqube-*.zip
 fi
 cd sonarqube-*

stop.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # Shortcut to stop server. It must be already built.