Newtonsoft.Json Assembly Not Found

Please take a look at this Travis CI job: https://travis-ci.org/Azure/azure-rest-api-specs/jobs/476409449

There is no recent releases or changes to any related files/packages. For the past few hours, the Travis CI jobs are failing with the following error:

An assembly specified in the application dependencies manifest (OpenApiDiff.deps.json) was not found:
package: ‘Newtonsoft.Json’, version: ‘9.0.1’
path: ‘lib/netstandard1.0/Newtonsoft.Json.dll’
at ChildProcess.exithandler (child_process.js:281:12)
at emitTwo (events.js:126:13)
at ChildProcess.emit (events.js:214:7)
at maybeClose (internal/child_process.js:915:16)
at Process.ChildProcess._handle.onexit (internal/child_process.js:209:5)

(P.S. This Job - https://travis-ci.org/Azure/azure-rest-api-specs/jobs/476401190 which ran 8 hours ago ran fine with no issues)

Can someone help me resolve this issue?

https://travis-ci.org/Azure/azure-rest-api-specs/jobs/477116041 has not, and https://travis-ci.org/Azure/azure-rest-api-specs/jobs/477065565 has not. I don’t know enough about Node.js or .NET to decipher what the real problem is, but I do not think the problem is with Travis CI.