Added all required dependencies

vendor/github.com/go-xorm/builder/cond_null.go

@@ -0,0 +1,47 @@
+package builder
+
+import "fmt"
+
+// IsNull
+type IsNull [1]string
+
+var _ Cond = IsNull{""}
+
+func (isNull IsNull) WriteTo(w Writer) error {
+	_, err := fmt.Fprintf(w, "%s IS NULL", isNull[0])
+	return err
+}
+
+func (isNull IsNull) And(conds ...Cond) Cond {
+	return And(isNull, And(conds...))
+}
+
+func (isNull IsNull) Or(conds ...Cond) Cond {
+	return Or(isNull, Or(conds...))
+}
+
+func (isNull IsNull) IsValid() bool {
+	return len(isNull[0]) > 0
+}
+
+// NotNull
+type NotNull [1]string
+
+var _ Cond = NotNull{""}
+
+func (notNull NotNull) WriteTo(w Writer) error {
+	_, err := fmt.Fprintf(w, "%s IS NOT NULL", notNull[0])
+	return err
+}
+
+func (notNull NotNull) And(conds ...Cond) Cond {
+	return And(notNull, And(conds...))
+}
+
+func (notNull NotNull) Or(conds ...Cond) Cond {
+	return Or(notNull, Or(conds...))
+}
+
+func (notNull NotNull) IsValid() bool {
+	return len(notNull[0]) > 0
+}