Merge pull request #1105 from sergey-shilov/cherrypick/INDY-1836_INDY-1926

INDY-1836/INDY-1926: bump plenum.

Author: ashcherbakov

Diff for: setup.py

@@ -56,7 +56,7 @@
     data_files=[(
         (BASE_DIR, ['data/nssm_original.exe'])
     )],
-    install_requires=['indy-plenum==1.6.56',
+    install_requires=['indy-plenum==1.6.57',
                       'python-dateutil',
                       'timeout-decorator==0.4.0'],
     setup_requires=['pytest-runner'],