[DEV] chore: add Node.js 10

[DanielRuf]

This change is 

[dsmilkov]

Thank you!

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Reviewed 1 of 1 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved, some commit checks failed.

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Comments from Reviewable

[nsthorat]

Hi @DanielRuf it looks like this broke the build. Would you mind taking a look?

https://travis-ci.org/tensorflow/tfjs-core/jobs/379663743

Thanks!

[nsthorat]

No worries. That line is a red herring.

I'm going to remove the check here since we always have the bstack key: #1044

I think the issue is with this:

(node:3909) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.
$ karma start --browsers='bs_firefox_mac,bs_chrome_mac' --singleRun
node[3930]: ../src/node_contextify.cc:628:static void node::contextify::ContextifyScript::New(const v8::FunctionCallbackInfo<v8::Value>&): Assertion `args[1]->IsString()' failed.
 1: node::Abort() [node]
 2: 0x876c55 [node]
 3: node::contextify::ContextifyScript::New(v8::FunctionCallbackInfo<v8::Value> const&) [node]
 4: v8::internal::FunctionCallbackArguments::Call(v8::internal::CallHandlerInfo*) [node]
 5: 0xacd2df [node]
 6: v8::internal::Builtin_HandleApiCall(int, v8::internal::Object**, v8::internal::Isolate*) [node]
 7: 0xf0c4f28427d

[DanielRuf]

See #1045, the dependencies were just outdated.

Exactly, there were peer dependencies of karma runner which produced this issue but I'm still surprised that it was directly merged.

I probably wanted to push another commit to update the dependencies (normally I use npm at home and not always yarn) so this went under my radar but finally forgot it (I think so).