Always use POSIX paths for ES imports

[bitpshr]

Type: bug

The following has been addressed in the PR:

• There is a related issue
• All code has been formatted with prettier as per the readme code style guidelines
• Unit or Functional tests are included in the PR

Description:

ES imports were botched on windows machines due to differences in the output of path.relative between win32 and POSIX operating systems. This PR modifies the usage of path.relative to use path.posix.relative since ES imports should always use POSIX path delimiters.

Resolves #15

[agubler]

@bitpshr Can we test this or it already covered? Looks like Appveyor is not setup correct for this repo so would never have run them on windows before.

[agubler]

@bitpshr Awesome setting up appveyor correctly and the previous commit on master fails.

Can you push a commit so that we get this PR to re-run on appveyor?

[bitpshr]

Thanks @agubler, ready for another review.

[agubler]

@bitpshr Cool, it doesn't look like that failing test was related to this change - which means we haven't covered the creation of these paths in a test (by covered I mean actually tested the values)?

Slightly off topic, we should probably add fixture tests for this repo to ensure that the output is actually correct! But we can do that as a follow up PR.

[agubler]

@bitpshr We should be able to use MockModules.ts, to assert the arguments of renderFiles that will cover these changes.

I don't think we have mock modules in this repo, but you should be able to copy it from @dojo/webpack-contrib and then use it similar to the build-time-render tests

[bitpshr]

@agubler Thanks for the reviews so far, ready for another. We were already using mockery directly in this test and had renderFiles stubs set up already, so I just hooked into those for now.

[agubler]

Thanks @bitpshr