* ignore unexported fields that are not embedded structs
* fix#74 [BREAKING CHANGE] Select#GroupBy and Select#OrderBy behavior change.
Previous, GroupBy and OrderBy only keep the columns in the last call. Now, all columns are kept.
* fix#75 add Struct#Columns/ColumnsForTag and Struct#Values/ValuesForTag
* remove a call to StructField.IsExported as it is not in go1.13
* refs #78 add new `fieldas` tag to set AS name for SELECT
* update docs
* fix#81 refactory struct field parser to make fieldas correct in all cases
* Add Gitter badge
* Fix insert ignore for postgres and sqlite.
* fix test
Co-authored-by: Michał Dobaczewski <[email protected]>
Co-authored-by: Huan Du <[email protected]>
Co-authored-by: The Gitter Badger <[email protected]>
Co-authored-by: Zhong Ren <[email protected]>
