FEATURE: allow "developer" account flagging via developers table

This mechanism for flagging developer accounts will eventually replace
DISCOURSE_DEVELOPER_EMAILS

spec/models/developer_spec.rb

@@ -0,0 +1,20 @@
+require 'rails_helper'
+
+describe Developer do
+  it "can correctly flag developer accounts" do
+    user = Fabricate(:user)
+    guardian = Guardian.new(user)
+
+    expect(guardian.is_developer?).to eq(false)
+
+    Developer.create!(user_id: user.id)
+
+    # not an admin so not a developer yet
+    expect(guardian.is_developer?).to eq(false)
+
+    user.update_columns(admin: true)
+
+    expect(guardian.is_developer?).to eq(true)
+  end
+end
+