enable py3.2 build in Travis

.travis.yml

@@ -10,13 +10,10 @@ matrix:
     dist: xenial
     sudo: false
     python: '2.7'
-# Something is broken about pysnmp->pysnmpcrypto->cryptography.
+  - os: linux
-# Somehow pysnmpcrypto chooses cryptography while it should
+    dist: xenial
-# pick pycryptodomex
+    sudo: false
-#  - os: linux
+    python: '3.2'
-#    dist: xenial
-#    sudo: false
-#    python: '3.2'
   - os: linux
     dist: xenial
     sudo: false