Test fails with Tarantool 2.8.1 or newer

[DifferentialOrange]

This commit has changes duplicate key message in Tarantool 2.8.1. Thus test run fails in Example() test of example_test.go file since Tarantool returns

Insert Error Duplicate key exists in unique index "primary" in space "test" with old tuple - [10, "test", "one"] and new tuple - [10, "test", "one"] (0x3)

while

go-tarantool/example_test.go

Line 197 in 56fe55c

// Insert Error Duplicate key exists in unique index 'primary' in space 'test' (0x3)

is expected.

To fix tests for Tarantool 2.x (since versions prior to 2.8.2 is EOL or will be there soon), example_test.go should be rewritten with some kind of fork based on Tarantool version or test case comparison should be replaced with regex.

[funny-falcon]

It seems there were copy-paste error from the beginning (11 != 10):

	// insert new tuple { 11, 1 }
	resp, err = client.Insert("test", &Tuple{Id: 10, Msg: "test", Name: "one"})

Or there should be two inserts: with error on duplicate and new one.

There is no need too make "fork". Just change fmt.Println("Insert Error", err) to something more clever.

[ylobankov]

This bug blocks resolving the issue tarantool/tarantool#6607. So we need to fix it ASAP.