added missing package requirements to installation guide.

Author: rahulmkhj

README.md

@@ -34,7 +34,7 @@ $ sudo apt upgrade
 Next install the required packages:
 
 ```
-$ sudo apt install apache2 libapache2-mod-php php7.0 php7.0-mbstring php7.0-mysql mysql-server freeradius freeradius-mysql freeradius-utils
+$ sudo apt install apache2 libapache2-mod-php php7.0 php-zip php7.0-mbstring php7.0-bcmath php7.0-mysql mysql-server freeradius freeradius-mysql freeradius-utils
 ```
 **NOTE:** 
 During the installation you'll be asked to set root password for MySQL server, choose a strong password