Add new user to sudoers and remove generic image user from sudoers

src/freedombone-config

                                if [[ $possible_username != $GENERIC_IMAGE_USERNAME ]]; then
                                    MY_USERNAME=$(cat $data)
                                    useradd -m -s /bin/bash $MY_USERNAME
-                                   echo "${MY_USERNAME}:$(printf `cat $IMAGE_PASSWORD_FILE`)" | chpasswd
-                                   break
+                                   if [ -d /home/$MY_USERNAME ]; then
+                                       echo "${MY_USERNAME}:$(printf `cat $IMAGE_PASSWORD_FILE`)" | chpasswd
+                                       # Add the user as a sudoer - they will be the new admin user
+                                       if ! grep -q "$MY_USERNAME  ALL=(ALL) ALL" /etc/sudoers; then
+                                           echo "$MY_USERNAME  ALL=(ALL) ALL" >> /etc/sudoers
+                                           # remove the generic image admin user from sudoers
+                                           sed -i "s|${GENERIC_IMAGE_USERNAME}.*||g" /etc/sudoers
+                                       fi
+                                       break
+                                   fi
                                fi
                            fi
                        fi