gocctl model v20200819 (#18)

* rename snake、came method

* new: generate model from data source

* add change log md

* update model doc

* update  doc

* beauty code

tools/goctl/model/sql/parser/parser.go

@@ -81,7 +81,7 @@ func Parse(ddl string) (*Table, error) {
 		}
 		column := index.Columns[0]
 		columnName := column.Column.String()
-		camelColumnName := stringx.From(columnName).Snake2Camel()
+		camelColumnName := stringx.From(columnName).ToCamel()
 		// by default, createTime|updateTime findOne is not used.
 		if camelColumnName == "CreateTime" || camelColumnName == "UpdateTime" {
 			continue