Refactor Project API to reflect changes upstream

projectile-project-root no longer returns `default-directory` if not in
a project (it returns nil). As such, doom-project-* functions (and their
uses) have been refactored.

+ doom-project-p & doom-project-root are aliases for
  projectile-project-p & projectile-project-root.
+ doom-project-{p,root,name,expand} now has a DIR argument (for
  consistency, since projectile-project-name and
  projectile-project-expand do not).
+ The nocache parameter is no longer necessary, as projectile's caching
  behavior is now more sane.
+ Removed some projectile advice/hacks that are no longer necessary.
+ Updated unit tests

modules/completion/ivy/autoload/ivy.el

@@ -217,11 +217,11 @@ The point of this is to avoid Emacs locking up indexing massive file trees."
   (interactive)
   (call-interactively
    (cond ((or (file-equal-p default-directory "~")
-              (when-let* ((proot (doom-project-root 'nocache)))
+              (when-let* ((proot (doom-project-root)))
                 (file-equal-p proot "~")))
           #'counsel-find-file)
 
-         ((doom-project-p 'nocache)
+         ((doom-project-p)
           (let ((files (projectile-current-project-files)))
             (if (<= (length files) ivy-sort-max-size)
                 #'counsel-projectile-find-file