Fix release names after Buster release

The patch is picked from Debian Bug #931614 and has been committed
upstream. It is slated for release in the first Debian 10 stable update.

This patch is fixes an FTBFS for devscripts.

Signed-off-by: Ritesh Raj Sarraf <ritesh.sarraf@collabora.com>

scripts/debchange.1

@@ -259,7 +259,7 @@ Don't append \fBdistro-name1\fR to the version on a derived
 distribution. Increment the Debian version.
 .TP
 .B \-\-bpo
-Increment the Debian release number for an upload to stretch-backports,
+Increment the Debian release number for an upload to buster-backports,
 and add a backport upload changelog comment.
 .TP
 .B \-\-stable

scripts/debchange.pl

@@ -162,7 +162,7 @@ Options:
          distribution name
   --bpo
          Increment the Debian release number for a backports upload
-         to "stretch-backports"
+         to "buster-backports"
   --stable
          Increment the Debian release number for a stable upload.
   -l, --local <suffix>
@@ -668,9 +668,9 @@ my $EMAIL        = 'EMAIL';
 my $DISTRIBUTION = 'UNRELEASED';
 # when updating the lines below also update the help text, the manpage and the testcases.
 my %dists
-  = (60, 'squeeze', 70, 'wheezy', 7, 'wheezy', 8, 'jessie', 9, 'stretch');
+  = (70, 'wheezy', 7, 'wheezy', 8, 'jessie', 9, 'stretch', 10, 'buster');
 my $lts_dist    = '8';
-my $latest_dist = '9';
+my $latest_dist = '10';
 # dist guessed from backports, SRU, security uploads...
 my $guessed_dist = '';
 my $CHANGES      = '';

test/test_debchange

@@ -218,10 +218,10 @@ verifyGuessedDistribution() {
 testGuessedDistribution() {
     verifyGuessedDistribution unstable -i unstable
     verifyGuessedDistribution experimental -i experimental
-    verifyGuessedDistribution jessie-backports -i jessie-backports
-    verifyGuessedDistribution jessie -i jessie
-    verifyGuessedDistribution unstable --bpo stretch-backports
-    verifyGuessedDistribution unstable --stable stretch
+    verifyGuessedDistribution stretch-backports -i stretch-backports
+    verifyGuessedDistribution stretch -i stretch
+    verifyGuessedDistribution unstable --bpo buster-backports
+    verifyGuessedDistribution unstable --stable buster
 }
 
 . shunit2