pyflakes for tests (later deepstate itself)

.travis.yml

@@ -4,6 +4,7 @@ sudo: true
 python:
 - "2.7"
 install:
+- pip install pyflakes
 - sudo apt-get -y update
 - sudo apt-get -y install build-essential gcc-multilib cmake python python-setuptools libffi-dev
 - if [ $DEEPSTATE_CMD = deepstate-manticore ]; then git clone https://github.com/Z3Prover/z3.git; fi
@@ -23,4 +24,5 @@ env:
 - TASK=ANGR DEEPSTATE_CMD=deepstate-angr
 - TASK=MANTICORE DEEPSTATE_CMD=deepstate-manticore
 script:
+- pyflakes tests/*.py
 - nosetests --verbose