Add the smove method to Kredis::Types::Set (#160)

* Add 'smove' method to Kredis::Types::Set

the Redis documentation currently supports the use of the `smove` method, this change make that method also available in kredis

 example:
     my_kredis_set.smove(another_kredis_set.key, value_to_move)

use case:
   when using sets as queues for a multi step process it is helpful to move values between sets: 
        queued -> issued
        issued -> completed
        issued -> failed & add back to queued for retying

https://redis.io/docs/latest/commands/smove/

* Add smove test coverage

* Update lib/kredis/types/set.rb

Co-authored-by: CoderMiguel <[email protected]>

* Update test/types/set_test.rb

Co-authored-by: CoderMiguel <[email protected]>

* linter feedback

* correct Gemfile.lock change

---------

Co-authored-by: David Heinemeier Hansson <[email protected]>

Author: CoderMiguel

Diff for: lib/kredis/types/set.rb

@@ -3,10 +3,13 @@
 class Kredis::Types::Set < Kredis::Types::Proxying
   prepend Kredis::DefaultValues
 
-  proxying :smembers, :sadd, :srem, :multi, :del, :sismember, :scard, :spop, :exists?, :srandmember
+  proxying :smembers, :sadd, :srem, :multi, :del, :sismember, :scard, :spop, :exists?, :srandmember, :smove
 
   attr_accessor :typed
-
+  def move(set, member)
+    destination = set.respond_to?(:key) ? set.key : set
+    smove(destination, member)
+  end
   def members
     strings_to_types(smembers || [], typed).sort
   end

Diff for: test/types/set_test.rb

@@ -101,6 +101,35 @@ class SetTest < ActiveSupport::TestCase
     assert_equal [ 1.5, 2.7 ], @set.sample(2).sort
   end
 
+  test "smove" do
+    @set.add(%w[ 1 2 ])
+    another_set = Kredis.set "another_set"
+    another_set.add(%w[ 3 ])
+
+    assert @set.smove(another_set.key, "2")
+    assert_equal %w[ 1 ], @set.members
+    assert_equal %w[ 2 3 ], another_set.members
+  end
+
+  test "move with set" do
+    @set.add(%w[ x y ])
+    another_set = Kredis.set "another_set"
+    another_set.add(%w[ z ])
+
+    assert @set.move(another_set, "y")
+    assert_equal %w[ x ], @set.members
+    assert_equal %w[ y z ], another_set.members
+  end
+
+  test "move with key" do
+    @set.add(%w[ a b ])
+    another_set = Kredis.set "another_set"
+    another_set.add(%w[ c ])
+
+    assert @set.move(another_set.key, "b")
+    assert_equal %w[ a ], @set.members
+    assert_equal %w[ b c ], another_set.members
+  end
 
   test "default" do
     @set = Kredis.set "mylist", default: %w[ 1 2 3 ]