Replace all "numeric" with "float8"

script/sql/create/9.demands.sql

@@ -4,7 +4,7 @@ create table demands
 (
   _order serial primary key
 , junction varchar(32) references junctions(id) not null
-, demand numeric not null
+, demand float8 not null
 , pattern varchar(32) references _pattern(id)
 , category text
 );