Change hex computation to be backward compatible with Python 3.6 (#129)

* Change hex computation to be backward compatible with Python 3.6

Author: saimonation

cterasdk/lib/crypto.py

@@ -111,7 +111,8 @@ def __init__(self, certificate):
 
     @property
     def sha1_fingerprint(self):
-        return self.certificate.fingerprint(hashes.SHA1()).hex(':', 1)
+        hexstr = self.certificate.fingerprint(hashes.SHA1()).hex()
+        return ':'.join([a + b for a, b in zip(hexstr[::2], hexstr[1::2])])
 
     @property
     def issuer(self):

docs/source/user_guides/Portal/GlobalAdmin.rst

@@ -144,6 +144,8 @@ Storage Nodes
 .. automethod:: cterasdk.core.buckets.Buckets.modify
    :noindex:
 
+.. code-block:: python
+
    """Modify an existing bucket, set it to read-delete only and dedicate it to 'mytenant'"""
    filer.buckets.modify('MainStorage', read_only=True, dedicated_to='mytenant')