Turned on directory layout tests for emmo and made them pytest (#706)

# Description
The test did not run by default.

## Type of change
<!-- Put an `x` in the box that applies. -->
- [ ] Bug fix.
- [ ] New feature.
- [ ] Documentation update.
- [ ] Test update.

## Checklist
<!-- Put an `x` in the boxes that apply. You can also fill these out
after creating the PR. -->

This checklist can be used as a help for the reviewer.

- [ ] Is the code easy to read and understand?
- [ ] Are comments for humans to read, not computers to disregard?
- [ ] Does a new feature has an accompanying new test (in the CI or unit
testing schemes)?
- [ ] Has the documentation been updated as necessary?
- [ ] Does this close the issue?
- [ ] Is the change limited to the issue?
- [ ] Are errors handled for all outcomes?
- [ ] Does the new feature provide new restrictions on dependencies, and
if so is this documented?

## Comments
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applicable. -->

---------

Co-authored-by: Jesper Friis <jesper-friis@users.noreply.github.com>

tests/test_utils_directory_layout.py

@@ -5,14 +5,14 @@
 from ontopy.utils import directory_layout
 
 
-# Requires that we have EMMO checked out locally
-if False:
-    emmo = get_ontology("../EMMO/emmo.ttl").load()
+def test_emmo_directory_layout():
+    emmo = get_ontology(
+        "https://raw.githubusercontent.com/emmo-repo/EMMO/1.0.0-beta4/emmo.ttl"
+    ).load()
     layout = directory_layout(emmo)
 
     # Map base IRIs to ontologies for easy access to all sub-ontologies
     omap = {o.base_iri: o for o in layout.keys()}
-
     # Base IRI of EMMO should not end with slash (/) !!!
     assert layout[omap["http://emmo.info/emmo/"]] == "emmo"
 
@@ -32,10 +32,6 @@
         layout[omap["http://emmo.info/emmo/disciplines/math#"]]
         == "disciplines/math"
     )
-    assert (
-        layout[omap["http://emmo.info/emmo/disciplines/units/siunits#"]]
-        == "disciplines/units/siunits"
-    )
     assert (
         layout[omap["http://emmo.info/emmo/mereocausality#"]]
         == "mereocausality/mereocausality"
@@ -60,17 +56,13 @@
         layout[omap["http://emmo.info/emmo/disciplines/math#"]]
         == "disciplines/math"
     )
-    assert (
-        layout[omap["http://emmo.info/emmo/disciplines/units/siunits#"]]
-        == "disciplines/units/siunits"
-    )
     assert (
         layout[omap["http://emmo.info/emmo/mereocausality#"]]
         == "mereocausality/mereocausality"
     )
 
 
-if True:
+def test_local_directory_layout():
     thisdir = Path(__file__).resolve().parent
     ontopath = thisdir / "testonto" / "testonto.ttl"
     onto = get_ontology(ontopath).load()