Add TEST_DATABASE_URL to the default .env

.env

@@ -6,4 +6,4 @@
 # variables in Settings > Build & Deploy > environment
 #
 # DATABASE_URL=postgres://user:pass@postgreshost.com:5432/database_name
-# BINARY_TARGET=rhel-openssl-1.0.x
+# TEST_DATABASE_URL=postgres://user:pass@postgreshost.com:5432/test_database_name

.env.defaults

@@ -6,5 +6,8 @@
 # schema.prisma defaults
 DATABASE_URL=file:./dev.db
 
+# location of the test database for api service scenarios (defaults to ./.redwood/test.db if not set)
+# TEST_DATABASE_URL=file:./.redwood/test.db
+
 # disables Prisma CLI update notifier
 PRISMA_HIDE_UPDATE_MESSAGE=true