fix validating email in strict mode (#976)

To enable strict mode in email validation, mode: :strict should be used, not strict_mode: true.

Author: manuelmeurer

lib/clearance/user.rb

@@ -150,7 +150,7 @@ module Validations
 
       included do
         validates :email,
-          email: { strict_mode: true },
+          email: { mode: :strict },
           presence: true,
           uniqueness: { allow_blank: true, case_sensitive: true },
           unless: :email_optional?

spec/models/user_spec.rb

@@ -5,15 +5,13 @@
   it { is_expected.to have_db_index(:remember_token) }
   it { is_expected.to validate_presence_of(:email) }
   it { is_expected.to validate_presence_of(:password) }
-  it { is_expected.to allow_value("foo;@example.com").for(:email) }
-  it { is_expected.to allow_value("[email protected]").for(:email) }
-  it { is_expected.to allow_value("[email protected]").for(:email) }
   it { is_expected.to allow_value("[email protected]").for(:email) }
   it { is_expected.to allow_value("[email protected]").for(:email) }
   it { is_expected.to allow_value("[email protected]").for(:email) }
   it { is_expected.not_to allow_value("example.com").for(:email) }
   it { is_expected.not_to allow_value("foo").for(:email) }
   it { is_expected.not_to allow_value("foo@").for(:email) }
+  it { is_expected.not_to allow_value("foo@bar").for(:email) }
 
   describe "#email" do
     it "stores email in down case and removes whitespace" do