Bump cryptography from 2.8 to 3.2

Bumps [cryptography](https://github.com/pyca/cryptography) from 2.8 to 3.2.
- [Release notes](https://github.com/pyca/cryptography/releases)
- [Changelog](https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/pyca/cryptography/compare/2.8...3.2)

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -19,7 +19,7 @@ Pysolar==0.6
 psutil==5.6.3
 joblib==0.17.0
 Fiona==1.8.9.post2
-cryptography==2.8
+cryptography==3.2
 pyOpenSSL==19.1.0
 scikit-learn==0.23.2
 laspy==1.6.0