fix(Setup): Soften the build-time errors to warnings for non-standard configurations
fix(Setup): Soften the build-time errors to warnings for non-standard configurations

* Fixes #322.

Change sass preprocessor error to a warning and update the wording.

* Wording change.

* Similar softening of the error when using less without the right bootstrap dependency.

* Refactor the warning message incantation into a method.

kaliber5/ember-bootstrap,jelhan/ember-bootstrap,jelhan/ember-bootstrap,kaliber5/ember-bootstrap