Increased the minimum pyflakes version; at least 0.9.2 is needed to deal correctly with the global declaration list in meeting migration 0056.

 - Legacy-Id: 14001

Author: levkowetz

requirements.txt

@@ -34,7 +34,7 @@ pathlib>=1.0
 pathlib2>=2.3.0
 Pillow>=3.0
 pyang>=1.7.2,<2.0
-pyflakes>=0.8.1
+pyflakes>=0.9.2
 pyquery>=1.2.13,!=1.2.14	# Pyqyery 1.2.14 fails on some selectors or stacked selectors
 python-dateutil>=2.2
 python-magic>=0.4.6