Translate keywords (#277)

* Translate keywords

* Add constraint

* Rename 000.376.sql to 000.377.sql

migrations/000.377.sql

@@ -0,0 +1,9 @@
+-- Add translations for keywords
+
+DROP TABLE IF EXISTS keywords_i18n;
+CREATE TABLE IF NOT EXISTS keywords_i18n (
+	id serial PRIMARY KEY,
+	keyword_id integer NOT NULL REFERENCES keywords(id),
+	locale_id integer NOT NULL REFERENCES locales(id),
+	value text
+);