Update README.md

[vyaspranjal33]

fixed LICENSE file extension in Link

Fixes

Checklist

• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I have read the [Contribution Guide] and my PR follows them.
• I updated my branch with the master branch.
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation about the functionality in the appropriate .md file
• I have added in line documentation to the code I modified

Short description of what this PR does:

If you have questions, please send an email to Sendgrid, or file a Github Issue in this repository.

[SendGridDX]

All committers have signed the CLA.

[aroach]

@vyaspranjal33 Can you take a look at why the build is failing?

[vyaspranjal33]

@aroach build fails because of "mono ./testrunner/NUnit.Runners.2.6.4/tools/nunit-console.exe UnitTest/bin/Release/UnitTest.dll -domain:None"

please fix it

[aroach]

It looks like it's failing when testing for LICENSE.txt: https://travis-ci.org/sendgrid/csharp-http-client/builds/447152699#L1724

[vyaspranjal33]

@aroach i fixed 404 error by changing License file link in badge ,i think it can be merged

[aroach]

@vyaspranjal33 yes, i see that. I didn't notice that the build had been failing on that LICENSE.txt check for a while now. You're good then! Thanks for the PR!

[vyaspranjal33]

@aroach please merge PRs , today is last day of Hacktoberfest 😅

[thinkingserious]

Hello @vyaspranjal33,

Thanks again for the PR!

We appreciate your contribution and look forward to continued collaboration. Thanks!

Team SendGrid DX