Move to directory when running postgresql queries

src/freedombone-utils-postgresql

 function add_postgresql_user {
     postgresql_username=$1
     postgresql_password=$2
+    cd /etc/postgresql
     if [[ "$3" != 'encrypt'* ]]; then
         sudo -u postgres psql -c "create user $postgresql_username password '$postgresql_password';"
     else
 
 function remove_postgresql_user {
     postgresql_username=$1
+    cd /etc/postgresql
     sudo -u postgres psql -c "drop user $postgresql_username"
 }
 
 function drop_database_postgresql {
     database_name="$1"
+    cd /etc/postgresql
     sudo -u postgres psql -c "drop database $database_name"
 }
 
 function run_system_query_postgresql {
     query=$1
+    cd /etc/postgresql
     sudo -u postgres psql -c "$query"
 }
 
 function run_query_postgresql {
     database_name=$1
     database_query=$2
+    cd /etc/postgresql
     sudo -u postgres psql -d $database_name -c "$database_query"
 }
 
 function run_query_postgresql_with_output {
     database_name=$1
     database_query=$2
+    cd /etc/postgresql
     output=$(sudo -u postgres psql -d $database_name -c << EOF
 $database_query
 EOF
 function initialise_database_postgresql {
     database_name=$1
     database_file=$2
+    cd /etc/postgresql
     sudo -u postgres psql $database_name < $database_file
     if [ ! "$?" = "0" ]; then
         exit 7238525
 flush privileges;
 quit" > $INSTALL_DIR/batch.sql
     chmod 600 $INSTALL_DIR/batch.sql
+    cd /etc/postgresql
     sudo -u postgres psql -d $database_name --file=$INSTALL_DIR/batch.sql
     shred -zu $INSTALL_DIR/batch.sql
 }