Support for go modules breaks compatibility of paths for go1.10

[marcusljx]

Please use the following questions as a guideline to help me answer
your issue/question without further inquiry. Thank you.

Which version of Elastic are you using?

• elastic.v2 (for Elasticsearch 1.x)
• elastic.v3 (for Elasticsearch 2.x)
• elastic.v5 (for Elasticsearch 5.x)
• elastic.v6 (for Elasticsearch 6.x)

Please describe the expected behavior

Using go1.10.2 with glide:

My glide configuration is:

- package: github.com/olivere/elastic
  version: ^6.0.0

My import statement is:

import "github.com/olivere/elastic"

Please describe the actual behavior

The client.go has an import error as it has this import statement:

	"github.com/olivere/elastic/v6/config"

The v6 directory is not imported by glide (used only with go modules), and hence on go1.10.2 this fails to build with the error:

vendor/github.com/olivere/elastic/client.go:24:2: cannot find package "github.com/olivere/elastic/v6/config"

Any steps to reproduce the behavior?

• Downgrade to go1.10.2
• Clone the repository to a project's .../vendor/github.com/olivere/elastic
• run go vet

[olivere]

For now, try:

- package: github.com/olivere/elastic
  version: 6.1.x

... and it should work again.

[olivere]

Not sure about Glide, but it should also work for a recent version of Go, i.e. 1.10.3 or later. Those have minimal module-awareness.

[olivere]

Sooner or later you probably have to move away from Glide, see their README. Right now, this doesn't help as dep has the same issues as Glide when it comes to supporting Go modules.

[olivere]

You should be able to update to 6.2.2 which works out of the box again. I reverted the change to the import path.