Add tests to assure that empty sections are supported

Ref: https://github.com/kaushalmodi/ox-hugo/issues/164

test/site/content-org/all-posts.org

@@ -443,7 +443,7 @@ This post must not be exported as it is tagged =noexport=.
 :EXPORT_FILE_NAME: commented-post
 :END:
 This post must not be exported as it is commented.
-* Section
+* Section                                                           :section:
 ** Articles
 :PROPERTIES:
 :EXPORT_HUGO_SECTION: articles
@@ -489,7 +489,37 @@ Here is the second post on Emacs.
 :EXPORT_HUGO_SECTION: zoo
 :EXPORT_FILE_NAME: post-in-zoo-section
 :END:
+#+begin_description
+Test where ~EXPORT_HUGO_SECTION~ is set in the post subtree itself.
+#+end_description
 This post will be created in the =zoo= section.
+** Null HUGO_SECTION                                             :root_level:
+*** Using empty EXPORT_HUGO_SECTION
+:PROPERTIES:
+:EXPORT_HUGO_SECTION:
+:EXPORT_FILE_NAME: root-level-content-empty-section
+:END:
+#+begin_description
+Case where ~EXPORT_HUGO_SECTION~ is set to nothing.
+#+end_description
+
+{{{oxhugoissue(164)}}}
+
+This post is created at the site root.
+*** Setting EXPORT_HUGO_SECTION to "/"
+:PROPERTIES:
+:EXPORT_HUGO_SECTION: /
+:EXPORT_FILE_NAME: root-level-content-section-set-to-slash
+:END:
+#+begin_description
+Case where ~EXPORT_HUGO_SECTION~ is set to ~/~.
+#+end_description
+
+{{{oxhugoissue(164)}}}
+
+This behaves the same as *not setting* ~EXPORT_HUGO_SECTION~ at all.
+
+This post is created at the site root.
 * Tables                                                              :table:
 ** Simple Table
 :PROPERTIES:

test/site/content/articles/article-1.md

@@ -1,6 +1,7 @@
 +++
 title = "Article 1"
 date = 2017-07-19T08:34:29-04:00
+tags = ["section"]
 draft = false
 +++
 

test/site/content/articles/article-2.md

@@ -1,6 +1,7 @@
 +++
 title = "Article 2"
 date = 2017-07-19T08:34:22-04:00
+tags = ["section"]
 draft = false
 +++
 

test/site/content/posts/emacs-post-1.md

@@ -1,7 +1,7 @@
 +++
 title = "Emacs Post 1"
 date = 2017-07-12T17:31:56-04:00
-tags = ["emacs", "foo"]
+tags = ["section", "emacs", "foo"]
 draft = false
 +++
 

test/site/content/posts/emacs-post-2.md

@@ -1,7 +1,7 @@
 +++
 title = "Emacs Post 2"
 date = 2017-07-12T17:31:56-04:00
-tags = ["emacs", "bar"]
+tags = ["section", "emacs", "bar"]
 draft = false
 +++
 

test/site/content/root-level-content-empty-section.md

@@ -0,0 +1,10 @@
++++
+title = "Using empty EXPORT_HUGO_SECTION"
+description = "Case where `EXPORT_HUGO_SECTION` is set to nothing."
+tags = ["section", "root-level"]
+draft = false
++++
+
+`ox-hugo` Issue #[164](https://github.com/kaushalmodi/ox-hugo/issues/164)
+
+This post is created at the site root.

test/site/content/root-level-content-section-set-to-slash.md

@@ -0,0 +1,12 @@
++++
+title = "Setting EXPORT_HUGO_SECTION to \"/\""
+description = "Case where `EXPORT_HUGO_SECTION` is set to `/`."
+tags = ["section", "root-level"]
+draft = false
++++
+
+`ox-hugo` Issue #[164](https://github.com/kaushalmodi/ox-hugo/issues/164)
+
+This behaves the same as **not setting** `EXPORT_HUGO_SECTION` at all.
+
+This post is created at the site root.

test/site/content/zoo/post-in-zoo-section.md

@@ -1,5 +1,7 @@
 +++
 title = "HUGO_SECTION set in post subtree"
+description = "Test where `EXPORT_HUGO_SECTION` is set in the post subtree itself."
+tags = ["section"]
 draft = false
 +++