Remove unnecessary table

db/schema.rb

@@ -260,13 +260,6 @@ ActiveRecord::Schema.define(version: 20180924201039) do
 
   add_index "chat_teams", ["namespace_id"], name: "index_chat_teams_on_namespace_id", unique: true, using: :btree
 
-  create_table "ci_build_schedules", id: :bigserial, force: :cascade do |t|
-    t.integer "build_id", null: false
-    t.datetime "execute_at", null: false
-  end
-
-  add_index "ci_build_schedules", ["build_id"], name: "index_ci_build_schedules_on_build_id", unique: true, using: :btree
-
   create_table "ci_build_trace_chunks", id: :bigserial, force: :cascade do |t|
     t.integer "build_id", null: false
     t.integer "chunk_index", null: false
@@ -2298,7 +2291,6 @@ ActiveRecord::Schema.define(version: 20180924201039) do
   add_foreign_key "boards", "namespaces", column: "group_id", on_delete: :cascade
   add_foreign_key "boards", "projects", name: "fk_f15266b5f9", on_delete: :cascade
   add_foreign_key "chat_teams", "namespaces", on_delete: :cascade
-  add_foreign_key "ci_build_schedules", "ci_builds", column: "build_id", on_delete: :cascade
   add_foreign_key "ci_build_trace_chunks", "ci_builds", column: "build_id", on_delete: :cascade
   add_foreign_key "ci_build_trace_section_names", "projects", on_delete: :cascade
   add_foreign_key "ci_build_trace_sections", "ci_build_trace_section_names", column: "section_name_id", name: "fk_264e112c66", on_delete: :cascade