Deprecated linux_distribution

The call from platform.linux_distribution was depdrecated in Python 3.7.

This patch solves this problem, using the recomended package distro.

Signed-off-by: Rodolfo García Peñas (kix) <kix@kix.es>

offlineimap/utils/distro_utils.py

@@ -5,6 +5,12 @@
 import platform
 import os
 
+# linux_distribution deprecated in Python 3.7
+try:
+    from platform import linux_distribution
+except ImportError:
+    from distro import linux_distribution
+
 # Each dictionary value is either string or some iterable.
 #
 # For the former we will just return the value, for an iterable
@@ -45,7 +51,7 @@ def get_os_name():
     os_name = platform.system().lower()
 
     if os_name.startswith('linux'):
-        distro_name = platform.linux_distribution()[0]
+        distro_name = linux_distribution()[0]
         if distro_name:
             os_name = os_name + "-%s" % distro_name.split()[0].lower()
         if os.path.exists('/etc/arch-release'):

requirements.txt

@@ -2,3 +2,4 @@
 gssapi[kerberos]
 portalocker[cygwin]
 rfc6555
+distro