Version updates in Dockerfile and docker-compose.yml

[pellejacobs]

Two minor updates to the Dockerfile and docker-compose.yml:

Dockerfile still references node:6, which recently lost LTS.

docker-compose.yml references postgres, which defaults to latest, currently postgres:12. However, this seemed to cause the following error:

db_1   | 2019-11-05 11:58:46.469 UTC [34] ERROR:  column r.consrc does not exist at character 212
db_1   | 2019-11-05 11:58:46.469 UTC [34] HINT:  Perhaps you meant to reference the column "r.conkey" or the column "r.conbin".
db_1   | 2019-11-05 11:58:46.469 UTC [34] STATEMENT:  SELECT x.nspname || '.' || x.relname as "Table", x.attnum as "#", x.attname as "Column", x."Type", case x.attnotnull when true then 'NOT NULL' else '' end as "NULL", r.conname as "Constraint", r.contype as "C", r.consrc, fn.nspname || '.' || f.relname as "F Key", d.adsrc as "Default" FROM (SELECT c.oid, a.attrelid, a.attnum, n.nspname, c.relname, a.attname, pg_catalog.format_type(a.atttypid, a.atttypmod) as "Type", a.attnotnull FROM pg_catalog.pg_attribute a, pg_namespace n, pg_class c WHERE a.attnum > 0 AND NOT a.attisdropped AND a.attrelid = c.oid and c.relkind not in ('S','v') and c.relnamespace = n.oid and n.nspname not in ('pg_catalog','pg_toast','information_schema')) x left join pg_attrdef d on d.adrelid = x.attrelid and d.adnum = x.attnum left join pg_constraint r on r.conrelid = x.oid and r.conkey[1] = x.attnum left join pg_class f on r.confrelid = f.oid left join pg_namespace fn on f.relnamespace = fn.oid where x.relname = 'asset' and x.nspname = 'public' order by 1,2;

Forcing postgres to postgres:11 fixed this. Similar issue here: pantsel/konga#462

[ArekSredzki]

Thanks for the contribution!