Merge pull request go-pg#1331 from go-pg/fix/normalize-bigserial

Normalize bigserial to bigint. Use pkSQLType only when creating a table.

Merge pull request go-pg#1316 from shahrukh330/v8

Merge copy fix into v8

readme: add v9

Merge pull request go-pg#1271 from go-pg/fix/go-mod-v9

go mod v9

Merge pull request go-pg#1181 from go-pg/fix/select-into-embedded-str…

…uct-ptr

Fix scanning into nil embedded struct pointer

Merge pull request go-pg#1147 from go-pg/fix/created-at

Fix MaxConnAge and MinIdleConns

Merge pull request go-pg#1132 from go-pg/fix/composite-scan-null

orm: fix scanning null values in composites

Fix ReadSlice usaage

Merge pull request go-pg#1123 from go-pg/fix/soft-delete-time-ptr

orm: fix nil time ptr

Merge pull request go-pg#1099 from go-pg/fix/with-ctx-race

Fix race in WithContext