Don't enforce trailing spaces on newlines in typedef-whitespace rule

[SteveVanOpstal]

Closes #1354

[palantirtech]

Thanks for your interest in palantir/tslint, @SteveVanOpstal! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[jkillian]

@SteveVanOpstal Just curious, does this fix #1521 as well?

[SteveVanOpstal]

Yes, the example he provides is basically the same as this test: https://github.com/SteveVanOpstal/tslint/blob/3bae5b9309b3485f0e87abe456f40627a2d1ae16/test/rules/typedef-whitespace/both/onespace/test.ts.lint#L347

[jkillian]

Looks good, thanks @SteveVanOpstal!