Minor refactoring to more apt names

Makefile

@@ -123,7 +123,7 @@ emacs-batch:
 	@echo ""
 	@echo "$(ORG_FILE) ::"
 	@$(EMACS) --batch --eval "(progn\
-	(setenv \"OX_HUGO_ELPA\" \"$(OX_HUGO_TMP_DIR)\")\
+	(setenv \"OX_HUGO_TMP_DIR\" \"$(OX_HUGO_TMP_DIR)\")\
 	(setenv \"TEST_ENABLED\" \"$(TEST_ENABLED)\")\
 	(load-file (expand-file-name \"setup-ox-hugo.el\" \"$(OX_HUGO_TEST_DIR)\"))\
 	)" $(ORG_FILE) \
@@ -140,7 +140,7 @@ ifeq ("$(EMACS_exists)","")
 endif
 	@echo "Emacs binary used: $(EMACS)"
 	@$(EMACS) --batch --eval "(progn\
-	(setenv \"OX_HUGO_ELPA\" \"$(OX_HUGO_TMP_DIR)\")\
+	(setenv \"OX_HUGO_TMP_DIR\" \"$(OX_HUGO_TMP_DIR)\")\
 	(load-file (expand-file-name \"setup-ox-hugo.el\" \"$(OX_HUGO_TEST_DIR)\"))\
 	(message \"[Version check] Emacs %s\" emacs-version)\
 	(message \"[Version check] %s\" (org-version nil :full))\

test/setup-ox-hugo.el

@@ -1,4 +1,4 @@
-;; Time-stamp: <2018-11-01 00:37:59 kmodi>
+;; Time-stamp: <2019-01-02 17:54:59 kmodi>
 
 ;; Setup to export Org files to Hugo-compatible Markdown using
 ;; `ox-hugo' in an "emacs -Q" environment.
@@ -29,7 +29,7 @@ minimum requirement for `ox-hugo'.  So set the environment
 variable OX_HUGO_DEFAULT_ORG to a value like 1 if using emacs 26
 or newer.")
 
-(defvar ox-hugo-elpa (let ((dir (getenv "OX_HUGO_ELPA")))
+(defvar ox-hugo-tmp-dir (let ((dir (getenv "OX_HUGO_TMP_DIR")))
                        (unless dir
                          (setq dir
                                (let* ((dir-1 (file-name-as-directory (expand-file-name user-login-name temporary-file-directory)))
@@ -39,7 +39,7 @@ or newer.")
                        (make-directory dir :parents)
                        dir))
 (when ox-hugo-test-setup-verbose
-  (message "ox-hugo-elpa: %s" ox-hugo-elpa))
+  (message "ox-hugo-tmp-dir: %s" ox-hugo-tmp-dir))
 
 (defvar ox-hugo-packages '(toc-org))
 (when ox-hugo-install-org-from-elpa
@@ -87,13 +87,13 @@ even if they are found as dependencies."
 (advice-add 'package-compute-transaction :filter-return #'ox-hugo-package-dependency-check-ignore)
 ;; (advice-remove 'package-compute-transaction #'ox-hugo-package-dependency-check-ignore)
 
-(if (and (stringp ox-hugo-elpa)
-         (file-exists-p ox-hugo-elpa))
+(if (and (stringp ox-hugo-tmp-dir)
+         (file-exists-p ox-hugo-tmp-dir))
     (progn
       ;; Load newer version of .el and .elc if both are available
       (setq load-prefer-newer t)
 
-      (setq package-user-dir (format "%selpa_%s/" ox-hugo-elpa emacs-major-version))
+      (setq package-user-dir (format "%selpa_%s/" ox-hugo-tmp-dir emacs-major-version))
 
       ;; Below require will auto-create `package-user-dir' it doesn't exist.
       (require 'package)
@@ -141,7 +141,7 @@ to be installed.")
           (message "Installing `%s' .." p)
           (package-install p))
         (setq ox-hugo-missing-packages '())))
-  (error "The environment variable OX_HUGO_ELPA needs to be set"))
+  (error "The environment variable OX_HUGO_TMP_DIR needs to be set"))
 
 ;; Remove Org that ships with Emacs from the `load-path' if installing
 ;; it from Elpa.