Commit vendor/ with LF-style line endings

[seanknox]

What this PR does / why we need it:

• Commits vendor/ with LF-style line endings to ensure vendor/ doesn't change every time glide install is run on Windows
• No functional change.
• acs-engine devs using Windows must set git config --global core.autocrlf input so git will automatically convert Windows-style CRLF endings to UNIX LF.

Which issue this PR fixes vendor/ was changing every time I ran make prereqs on macOS. This will commit + Windows devs setting core.autocrlf=input in their gitconfig should prevent noise.

Special notes for your reviewer:

Release note:

---

This change is 

[seanknox]

@squillace @anhowe @colemickens To test, I did the following:

1. ran glide install on my Mac which repulls dependencies with UNIX LF line endings
2. committed (this PR)
3. On a Windows 10 VM with acs-engine, ran glide install
4. Confirmed with git status that vendor/ was unchanged

If either of y'all are on Windows, you can test by cloning/pulling, git checkout fix-line-encodings, and running make prereqs (assuming you have make on your box. Ultimately what's important is that you download and run glide:

prereqs:
	go get github.com/Masterminds/glide
	go get github.com/jteeuwen/go-bindata/...
	glide install

[seanknox]

Oh, and you'll need to configure Git to convert CRLF to LF on commit:

just for this repo:
git config core.autocrlf input

globally (all projects you use git with)
git config --global core.autocrlf input

[seanknox]

@acs-bot test this please

[seanknox]

@acs-bot test this please

[JackQuincy]

How does this behave when you check it out in Linux?

[seanknox]

Didn't try Linux, though all *NIX OSes (Linux, macOS, etc.) use LF-style line endings.

[edit]: and because they use LF-style endings, it will work fine on them. Sorry I left the key piece of info out.

[JackQuincy]

LGTM, pulled the branch locally and in windows when I use the dockerfile like we ask devs to I had correct behavior.

[seanknox]

Awesome. I confirmed Linux does the right thing too (just in case my neckbeard lore was flimsy):

$ docker run --rm -it ubuntu bash
root@29a1767814c2:~ go get github.com/Azure/acs-engine && cd $GOPATH/src/github.com/Azure/acs-engine
root@29a1767814c2:~/go/src/github.com/Azure/acs-engine# git checkout fix-line-encodings
root@29a1767814c2:~/go/src/github.com/Azure/acs-engine# make prereqs
go get github.com/Masterminds/glide
go get github.com/jteeuwen/go-bindata/...
glide install
[INFO]	Downloading dependencies. Please wait...
[INFO]	--> Found desired version locally github.com/Azure/azure-sdk-for-go 5841475edc7c8725d79885d635aa8956f97fdf0e!
[INFO]	--> Found desired version locally github.com/Azure/go-autorest 58f6f26e200fa5dfb40c9cd1c83f3e2c860d779d!
[INFO]	--> Found desired version locally github.com/dgrijalva/jwt-go 6c8dedd55f8a2e41f605de6d5d66e51ed1f299fc!
...
root@29a1767814c2:~/go/src/github.com/Azure/acs-engine# git status
On branch fix-line-encodings
Your branch is up-to-date with 'origin/fix-line-encodings'.
nothing to commit, working directory clean

[seanknox]

CI timed out after nearly an hour. We'll fix this. Re-running again.

Error [deploy_template test-acs-kubernetes-westus-472-0]
SUCCESS [cleanup test-acs-kubernetes-westus-472-0]
Error: Test failed
Build step 'Execute shell' marked build as failure
Archiving artifacts
Setting status of 1ecacee64c597a9f760b3779c944f230de966977 to FAILURE with url https://jenkins.azure-containers.io/job/acs-engine-pr/472/ and message: 'Build finished. '
Finished: FAILURE

[seanknox]

@acs-bot test this please