Merge pull request #11 from giannisdoukas/fix-requirements

set cwltool requirement to the official

requirements.txt

@@ -1,22 +1,9 @@
-appnope>=0.1.0
-git+https://github.com/giannisdoukas/cwltool.git#egg=cwltool
-decorator>=4.4.1
-html5lib>=1.0.1
-ipython-genutils>=0.2.0
-jedi>=0.16.0
+cwltool>=3.0.20200706173533
 jsonschema>=3.2.0
 jupyter-client>=5.3.4
 jupyter-core>=4.6.3
-parso>=0.6.1
-pickleshare>=0.7.5
 psutil>=5.7.0
-python-dateutil>=2.8.1
-pyzmq>=18.1.1
 ruamel.yaml<=0.16.5,>=0.12.4
-six>=1.14.0
-tornado>=6.0.3
-traitlets>=4.3.3
-uritools>=3.0.0
 PyYAML>=5.3.1
 pandas>=1.0.4
 notebook>=6.0.3