change tested versions

.azure-pipelines/azure-pipelines-external.yml

@@ -14,18 +14,13 @@ jobs:
         python.version: 3.9
         pystan.version: "latest"
         pymc3.version: "latest"
-        pyro.version: "latest"
-        pytorch.version: "latest"
         emcee.version: "latest"
         name: "External latest"
       Python_39_PyStan_3_PyMC3_gh_Pyro_1_Emcee_2_TF_1:
         python.version: 3.9
         pystan.version: "preview"
         pymc3.version: "github"
-        pyro.version: 1.2
-        pytorch.version: 1.4
         emcee.version: 2
-        tensorflow.version: 1
         name: "External special"
 
   steps:
@@ -48,12 +43,6 @@ jobs:
       python -m pip install --upgrade pip
       python -m pip install wheel
 
-      if [ "$(pytorch.version)" = "latest" ]; then
-          python -m pip --no-cache-dir install torch -f https://download.pytorch.org/whl/cpu/torch_stable.html
-      else
-          python -m pip --no-cache-dir install torch=="$(pytorch.version)" -f https://download.pytorch.org/whl/cpu/torch_stable.html
-      fi
-
       if [ "$(pystan.version)" = "latest" ]; then
           python -m pip --no-cache-dir install pystan
       else
@@ -66,12 +55,6 @@ jobs:
           fi
       fi
 
-      if [ "$(pyro.version)" = "latest" ]; then
-          python -m pip --no-cache-dir install pyro-ppl
-      else
-          python -m pip --no-cache-dir install pyro-ppl=="$(pyro.version)"
-      fi
-
       if [ "$(emcee.version)" = "latest" ]; then
           python -m pip --no-cache-dir install emcee
       else
@@ -85,6 +68,7 @@ jobs:
       fi
 
       grep -Ev '^pystan|^pyro|^emcee|^pymc3' requirements-external.txt | xargs python -m pip install
+
     displayName: 'Install packages'
 
   - script: |