Remove Deprecated EmailValidator

The email validator was deprecated Mar 15th 2018 almost 18 months ago
as part of: 6d8fd3c

The deprecation warning was part of v2.6.0rc1, and remains to this day
in v2.10.0.beta1 I think it's time to remove it altogether. It's been
4 minor version upgrades now.

core/lib/spree/core/validators/email.rb

@@ -21,10 +21,3 @@ def validate_each(record, attribute, value)
  end
  end
 end
-
-# @private
-EmailValidator = ActiveSupport::Deprecation::DeprecatedConstantProxy.new(
- 'EmailValidator',
- 'Spree::EmailValidator',
- message: "EmailValidator is deprecated! Use Spree::EmailValidator instead.\nChange `validates :email, email: true` to `validates :email, 'spree/email' => true`\n"
-)

core/spec/lib/spree/core/validators/email_spec.rb

@@ -12,27 +12,27 @@ class Tester
 
  let(:valid_emails) {
  [
- '[email protected]',
- '[email protected]',
- '[email protected]',
- '[email protected]',
- '[email protected]',
- '[email protected]',
- '[email protected]'
- ]
+  '[email protected]',
+  '[email protected]',
+  '[email protected]',
+  '[email protected]',
+  '[email protected]',
+  '[email protected]',
+  '[email protected]'
+  ]
  }
  let(:invalid_emails) {
  [
- 'invalid [email protected]',
- '[email protected]',
- '[email protected]',
- '@email.com',
- '[email protected]',
- 'invalidemailemail.com',
- '@[email protected]',
- 'invalid@[email protected]',
- 'invalid.email@@email.com'
- ]
+  'invalid [email protected]',
+  '[email protected]',
+  '[email protected]',
+  '@email.com',
+  '[email protected]',
+  'invalidemailemail.com',
+  '@[email protected]',
+  'invalid@[email protected]',
+  'invalid.email@@email.com'
+  ]
  }
 
  it 'validates valid email addresses' do