Use uints for all timestamps.

Sphinx 3.3 removes all the timestamp attribute types in favour for uints. Functionally, it’s the same behaviour from Thinking Sphinx’s perspective anyway, as times are being translated into UNIX timestamp integers.

lib/thinking_sphinx/active_record/attribute/sphinx_presenter.rb

@@ -4,7 +4,7 @@ class ThinkingSphinx::ActiveRecord::Attribute::SphinxPresenter
   SPHINX_TYPES = {
     :integer   => :uint,
     :boolean   => :bool,
-    :timestamp => :timestamp,
+    :timestamp => :uint,
     :float     => :float,
     :string    => :string,
     :bigint    => :bigint,

lib/thinking_sphinx/real_time/index.rb

@@ -65,12 +65,10 @@ def append_unique_attribute(collection, attribute)
 
   def collection_for(attribute)
     case attribute.type
-    when :integer, :boolean
+    when :integer, :boolean, :timestamp
       attribute.multi? ? @rt_attr_multi : @rt_attr_uint
     when :string
       @rt_attr_string
-    when :timestamp
-      @rt_attr_timestamp
     when :float
       @rt_attr_float
     when :bigint

spec/thinking_sphinx/active_record/sql_source_spec.rb

@@ -325,14 +325,14 @@
       expect(source.sql_attr_string).to include('name')
     end
 
-    it "adds timestamp attributes to sql_attr_timestamp" do
+    it "adds timestamp attributes to sql_attr_uint" do
       source.attributes << double('attribute')
       allow(presenter).to receive_messages :declaration => 'created_at',
-        :collection_type => :timestamp
+        :collection_type => :uint
 
       source.render
 
-      expect(source.sql_attr_timestamp).to include('created_at')
+      expect(source.sql_attr_uint).to include('created_at')
     end
 
     it "adds float attributes to sql_attr_float" do