make DB an object to avoid compiler warning about reflectiveCalls

When I try to access the DB.INSTALL namespace it gives me

[warn] ...DatomicMigrate.scala:34: reflective access of structural type member value INSTALL should be enabled
[warn] by making the implicit value scala.language.reflectiveCalls visible.
[warn] This can be achieved by adding the import clause 'import scala.language.reflectiveCalls'
[warn] or by setting the compiler option -language:reflectiveCalls.
[warn] See the Scala docs for value scala.language.reflectiveCalls for a discussion
[warn] why the feature should be explicitly enabled.
[warn]     db.datoms(Database.AVET, Namespace.DB.INSTALL / "attribute").foreach { datomic =>
[warn]                                           ^

use an object instead of allowing reflective calls

sdjlfjs