fix py3.6 compat

Author: mr-c

requirements.txt

@@ -1,6 +1,7 @@
 requests>=2.4.3
 ruamel.yaml>=0.15,<0.17.22
 rdflib>=4.2.2,<6.2
+rdflib>= 4.2.2, < 6.0.0;python_version<='3.6'
 shellescape>=3.4.1,<3.9
 schema-salad>=8.2.20211104054942,<9
 prov==1.5.1

setup.py

@@ -110,6 +110,7 @@
         # https://github.com/ionrock/cachecontrol/issues/137
         "ruamel.yaml >= 0.15, < 0.17.22",
         "rdflib >= 4.2.2, < 6.2.0",
+        "rdflib >= 4.2.2, < 6.0.0;python_version<='3.6'",
         "shellescape >= 3.4.1, < 3.9",
         "schema-salad >= 8.2.20211104054942, < 9",
         "mypy-extensions",
@@ -134,7 +135,7 @@
         "mock >= 2.0.0",
         "pytest-mock >= 1.10.0",
         "arcp >= 0.2.0",
-        "rdflib-jsonld >= 0.4.0",
+        "rdflib-jsonld>=0.4.0, <= 0.6.1;python_version<='3.6'",
     ],
     entry_points={"console_scripts": ["cwltool=cwltool.main:run"]},
     zip_safe=True,

test-requirements.txt

@@ -4,5 +4,5 @@ mock >= 2.0.0
 pytest-mock >= 1.10.0
 pytest-cov
 arcp >= 0.2.0
-rdflib-jsonld >= 0.4.0
+rdflib-jsonld>=0.4.0, <= 0.6.1;python_version<='3.6'
 -rrequirements.txt