Support MySQL8

Results seem to be returned in reverse order now, so I'm fixing the
tests for that.

See #69

docker-compose.yml

@@ -2,7 +2,8 @@ version: '2.0'
 
 services:
   db:
-    image: mysql:5.7
+    image: mysql:8.0-debian
+    command: --default-authentication-plugin=mysql_native_password
     environment:
       MYSQL_ALLOW_EMPTY_PASSWORD: 'yes'
     volumes:

test/unit/push_qst_channel_message_job_test.rb

@@ -73,8 +73,8 @@ def setup
   end
 
   test "two messages no previous last id but only one confirmed" do
-    @msg1 = AoMessage.make :account => @channel.account, :channel => @channel, :state => 'queued', :timestamp => Time.now
     @msg2 = AoMessage.make :account => @channel.account, :channel => @channel, :state => 'queued', :timestamp => Time.now + 1
+    @msg1 = AoMessage.make :account => @channel.account, :channel => @channel, :state => 'queued', :timestamp => Time.now
 
     @client.expects(:get_last_id).returns(nil)
     @client.expects(:put_messages).with([@msg1.to_qst, @msg2.to_qst]).returns(@msg1.guid)

test/unit/telemetry/channels_by_kind_collector_test.rb

@@ -25,14 +25,14 @@ def setup
     @end = @now
     @period = InsteddTelemetry::Period.new beginning: @beginning, end: @end
 
+    Pop3Channel.make created_at: @end - 3.days
+    Pop3Channel.make created_at: @end - 8.days
+    Pop3Channel.make created_at: @end + 3.days
+
     QstClientChannel.make created_at: @end - 1.day
     QstClientChannel.make created_at: @end - 10.days
     QstClientChannel.make created_at: @end - 365.days
     QstClientChannel.make created_at: @end + 1.day
-
-    Pop3Channel.make created_at: @end - 3.days
-    Pop3Channel.make created_at: @end - 8.days
-    Pop3Channel.make created_at: @end + 3.days
   end
 
   test 'should collect channels grouped by kind' do