Fixed #2086 by adding support for Windows Named Pipes in volumes

[ericdalling]

Summary
This pull request fixes issue #2086, allowing Windows containers to mount Named Pipes (i.e. Mounting the .\pipe\docker_engine).

Implementation details
There is a regular expression to check if the mount path is using named pipes, is so, it bypasses the call to the filepath.Clean function that breaks the named pipes path.

Testing
I ran the unit and integration tests on a Windows machine
New tests cover the changes: yes

Description for the changelog
Enables support for mounting named pipes to Windows docker containers in ECS

Licensing
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[ericdalling]

@yumex93 and @fenxiong this is the new PR that I opened. Please review and let me know your feedback. Thanks!

[fenxiong]

@ericdalling make static-check is failing. can you run make gofmt to fix formatting? thanks.

[ericdalling]

@ericdalling make static-check is failing. can you run make gofmt to fix formatting? thanks.

I ran the make gofmt and fixed the formatting issues. Thanks!

[yhlee-aws]

@ericdalling Thank you for the contribution!