Support for `.jsx` extension

[raulmatei]

We use .jsx for React components and we get errors when importing files that have .jsx extension but without adding the extension in the import statement.

ex:

import x from './x';` // the file is x.jsx

Adding the extension to the import statement resolves the errors. Can this extension be added into https://github.com/zertosh/eslint-plugin-dependencies/blob/master/no-unresolved.js#L13, or a better solution would be to add an option for the extensions array to be overridden.