Reorganize unit-tests and test workflow

+ Moved unit tests out of tests/ and into their respective modules.
+ Rewrite makefile and added these tasks:
  + <MODULE>/<SUBMODULE> -- byte-compile a specific module
  + test:<MODULE>/<SUBMODULE> -- runs tests for a specific module
  + testi -- run tests in an interactive session of Emacs (WIP)
  + run -- opens an Emacs session with this config; useful when it is in
    a non-standard location.

modules/feature/evil/test/autoload-files.el

@@ -0,0 +1,46 @@
+;; -*- no-byte-compile: t; -*-
+;;; feature/evil/test/autoload-files.el
+
+(defmacro -with-temp-files! (src dest &rest body)
+  "Run FORMS in the context of a temporary package setup (as in, it won't
+affects your Emacs packages)."
+  (declare (indent 2) (doc-string 3))
+  `(let ((it ,src)
+         (other ,dest))
+     (with-temp-file it
+       (insert "Hello world"))
+     (unwind-protect
+         (progn
+           (should (file-exists-p it))
+           (find-file-literally it)
+           (should (equal (buffer-string) "Hello world"))
+           (should (equal (buffer-file-name) it))
+           (let ((inhibit-message (not doom-debug-mode)))
+             ,@body))
+       (ignore-errors (delete-file it))
+       ,(if dest `(ignore-errors (delete-file other))))))
+
+;;
+(def-test! move-this-file
+  ":mv"
+  (-with-temp-files! "/tmp/doom-buffer" "/tmp/doom-buffer-new"
+    (should-error (+evil:move-this-file it))
+    (should (+evil:move-this-file other t))
+    (should (file-exists-p other))
+    (should (not (file-exists-p it)))))
+
+(def-test! copy-this-file
+  ":cp"
+  (-with-temp-files! "/tmp/doom-buffer-2" "/tmp/doom-buffer-2-new"
+    (should-error (+evil:copy-this-file it))
+    (should (+evil:copy-this-file other t))
+    (should (file-exists-p other))
+    (should (file-exists-p it))))
+
+(def-test! delete-this-file
+  ":rm"
+  (-with-temp-files! "/tmp/doom-buffer-3" nil
+    (should-error (+evil:delete-this-file "this-file-does-not-exist"))
+    (should (+evil:delete-this-file nil t))
+    (should (not (file-exists-p it)))))
+