Add a table to configure which build servers build what

sqitch/deploy/build_servers_build_config.sql

@@ -0,0 +1,12 @@
+-- Deploy guix-data-service:build_servers_build_config to pg
+
+BEGIN;
+
+CREATE TABLE build_servers_build_config (
+    build_server_id integer REFERENCES build_servers(id),
+    system varchar NOT NULL,
+    target varchar NOT NULL,
+    PRIMARY KEY (build_server_id, system, target)
+);
+
+COMMIT;

sqitch/revert/build_servers_build_config.sql

@@ -0,0 +1,7 @@
+-- Revert guix-data-service:build_servers_build_config from pg
+
+BEGIN;
+
+DROP TABLE build_servers_build_config;
+
+COMMIT;

sqitch/sqitch.plan

@@ -41,3 +41,4 @@ builds_add_derivation_output_details_set_id 2019-12-07T18:25:38Z Christopher Bai
 derivations_hash_index 2019-12-24T22:54:19Z Christopher Baines <mail@cbaines.net> # Add index on derivations for the hash component of the filename
 add_derivation_source_file_nars 2019-12-28T20:37:06Z Christopher Baines <mail@cbaines.net> # Add table for derivation source file nars
 derivation_source_files_store_path_hash_index 2019-12-29T17:53:08Z Christopher Baines <mail@cbaines.net> # Add index on the hash part of the derivation source files store path
+build_servers_build_config 2020-01-05T12:06:13Z Christopher Baines <mail@cbaines.net> # Add build_servers_build_config table

sqitch/verify/build_servers_build_config.sql

@@ -0,0 +1,7 @@
+-- Verify guix-data-service:build_servers_build_config on pg
+
+BEGIN;
+
+-- XXX Add verifications here.
+
+ROLLBACK;