enforce Bullet in specs

refs CORE-1541

Change-Id: Ic8a50cd43c4789e6de5eeca330ae590a1f48bc4c
Reviewed-on: https://gerrit.instructure.com/159904
Tested-by: Jenkins
Reviewed-by: Rob Orton <rob@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>

config/environments/bullet.rb

@@ -5,6 +5,7 @@ Bullet.unused_eager_loading_enable = false
 Bullet.counter_cache_enable = false
 
 Bullet.rails_logger = true
+Bullet.raise = true
 Bullet.stacktrace_excludes = [
   # chains to root_topic, but it should be cached fairly often, so we don't want
   # to unnecessarily preload