Step 1. Edit in apache2.conf
cd /etc/apache2
sudo gedit apache2.conf
Step 2. Here in apache2.conf change
<Directory /var/www/>
Options Indexes FollowSymLinks
AllowOverride None
Require all granted
</Directory>
Step 3. to
<Directory /var/www/>
Options Indexes FollowSymLinks
AllowOverride All
Require all granted
</Directory>
done!