Replace all "numeric" with "float8"

script/sql/create/7.valves.sql

@@ -7,10 +7,10 @@ create table valves
   id varchar(32) primary key references _link(id)
 , node1 varchar(32) references _node(id) not null
 , node2 varchar(32) references _node(id) not null
-, diameter numeric not null
+, diameter float8 not null
 , type valves_type not null
 , setting text not null
-, minor_loss numeric not null
+, minor_loss float8 not null
 );
 
 -- delete when delete node1