Bump cryptography from 2.6.1 to 3.2 (#553)

Author: felipediel

requirements.txt

@@ -1 +1 @@
-cryptography==2.6.1
+cryptography==3.2

setup.py

@@ -15,7 +15,7 @@
     url="http://github.com/mjg59/python-broadlink",
     packages=find_packages(),
     scripts=[],
-    install_requires=["cryptography>=2.1.1"],
+    install_requires=["cryptography>=3.2"],
     description="Python API for controlling Broadlink IR controllers",
     classifiers=[
         "Development Status :: 4 - Beta",