setup: pin yadage==0.20.1

- `yadage==0.20.2` is failing at the workflow engine level
- it requires to pin reana-commons to 0.8.3.a1, since 0.8.3 requires `yadage~=0.20.2`

requirements.txt

@@ -41,7 +41,7 @@ pyrsistent==0.18.0        # via jsonschema
 python-dateutil==2.8.2    # via bravado, bravado-core
 pytz==2021.3              # via bravado-core, fs
 pyyaml==5.4.1             # via bravado, bravado-core, packtivity, reana-commons, yadage, yadage-schemas
-reana-commons[yadage]==0.8.3  # via reana-workflow-engine-yadage (setup.py)
+reana-commons[yadage]==0.8.3a1  # via reana-workflow-engine-yadage (setup.py)
 requests[security]==2.26.0  # via bravado, packtivity, reana-workflow-engine-yadage (setup.py), yadage, yadage-schemas
 rfc3987==1.3.8            # via jsonschema, reana-workflow-engine-yadage (setup.py)
 simplejson==3.17.5        # via bravado, bravado-core
@@ -54,7 +54,7 @@ vine==1.3.0               # via amqp
 webcolors==1.11.1         # via jsonschema
 werkzeug==2.0.2           # via reana-commons
 yadage-schemas==0.10.6    # via packtivity, reana-commons, yadage
-yadage==0.20.2            # via reana-commons
+yadage==0.20.1            # via reana-commons
 
 # The following packages are considered to be unsafe in a requirements file:
 # setuptools

setup.py

@@ -47,7 +47,7 @@
     "mock>=3.0,<4",
     "pydot>=1.0.29",  # FIXME needed only if yadage visuale=True.
     "pydotplus>=2.0.2",  # FIXME needed only if yadage visuale=True.
-    "reana-commons[yadage]>=0.8.3,<0.9.0",
+    "reana-commons[yadage]==0.8.3a1",  # FIXME: Unpin when yadage>=0.20.2 is compatible
     "requests>=2.25.1",
     "rfc3987==1.3.8",  # FIXME remove once yadage-schemas solves yadage deps.
 ]