sqlite3 port of the DDL changes (#20, #88)

controller/store/sql/sqlite3/002_v0_3_0_frontend_selection.sql

@@ -0,0 +1,27 @@
+-- +migrate Up
+
+create table frontends (
+  id                    serial              primary key,
+  environment_id        integer             references environments(id),
+  z_id                  varchar(32)         not null unique,
+  name                  varchar(64)         unique,
+  created_at            datetime            not null default(strftime('%Y-%m-%d %H:%M:%f', 'now')),
+  updated_at            datetime            not null default(strftime('%Y-%m-%d %H:%M:%f', 'now'))
+);
+
+-- environments.account_id should allow NULL; environments with NULL account_id are "ephemeral"
+alter table environments rename to environments_old;
+create table environments (
+  id                    integer             primary key,
+  account_id            integer             references accounts(id) on delete cascade,
+  description           string,
+  host                  string,
+  address               string,
+  z_id                  string              not null unique,
+  created_at            datetime            not null default(strftime('%Y-%m-%d %H:%M:%f', 'now')),
+  updated_at            datetime            not null default(strftime('%Y-%m-%d %H:%M:%f', 'now')),
+
+  constraint chk_z_id check (z_id <> '')
+);
+insert into environments select * from environments_old;
+drop table environments_old;