in postgresql, pageviews.timestamp column should be without timezone

pkg/datastore/sqlstore/migrations/postgres/22_alter_page_stats_table.sql

@@ -9,7 +9,7 @@ CREATE TABLE page_stats(
    bounce_rate FLOAT NOT NULL,
    known_durations INTEGER NOT NULL DEFAULT 0,
    avg_duration FLOAT NOT NULL,
-   ts TIMESTAMP NOT NULL
+   ts TIMESTAMP WITHOUT TIME ZONE NOT NULL
 );
 INSERT INTO page_stats 
     SELECT site_id, hostname_id, pathname_id, pageviews, visitors, entries, bounce_rate, known_durations, avg_duration, (date || ' 00:00:00')::timestamp

pkg/datastore/sqlstore/migrations/postgres/23_alter_referrer_stats_table.sql

@@ -9,7 +9,7 @@ CREATE TABLE referrer_stats(
     bounce_rate FLOAT NOT NULL, 
     known_durations INTEGER NOT NULL DEFAULT 0, 
     avg_duration FLOAT NOT NULL, 
-    ts TIMESTAMP NOT NULL 
+    ts TIMESTAMP WITHOUT TIME ZONE NOT NULL 
 );
 INSERT INTO referrer_stats 
     SELECT site_id, hostname_id, pathname_id, groupname, pageviews, visitors, bounce_rate, known_durations, avg_duration, (date || ' 00:00:00')::timestamp

pkg/datastore/sqlstore/migrations/postgres/24_alter_site_stats_table.sql

@@ -7,7 +7,7 @@ CREATE TABLE site_stats(
    bounce_rate FLOAT NOT NULL,
    known_durations INTEGER NOT NULL DEFAULT 0,
    avg_duration FLOAT NOT NULL,
-   ts TIMESTAMP NOT NULL
+   ts TIMESTAMP WITHOUT TIME ZONE NOT NULL
 );
 INSERT INTO site_stats 
     SELECT site_id, pageviews, visitors, sessions, bounce_rate, known_durations, avg_duration, (date || ' 00:00:00')::timestamp

pkg/datastore/sqlstore/migrations/postgres/26_alter_pageviews_table.sql

@@ -0,0 +1,7 @@
+-- +migrate Up
+
+ALTER TABLE pageviews ALTER COLUMN timestamp TYPE TIMESTAMP WITHOUT TIME ZONE;
+
+-- +migrate Down
+
+ALTER TABLE pageviews ALTER COLUMN timestamp TYPE TIMESTAMP WITH TIME ZONE;