Implemented most useful patterns.
Skipped %U, %W (not ISO week number) and modifiers E and O.
package main
import(
"fmt"
"time"
"github.com/dstarodubtsev/go_strftime"
)
func main(){
// "2015-06-23 17:57:05", as expected
fmt.Println(go_strftime.Strftime("%Y-%m-%d %H:%M:%S", time.Now()))
}