No longer run master branch through CI.

The integration branch will be run through CI and then pushed to master with github status checks.

.travis.yml

@@ -1,6 +1,5 @@
 branches:
   only:
-    - master
     - integration
     - /-ci$/
 

doc/xml/release.xml

@@ -158,6 +158,10 @@
                         <p>Add unit tests for the <code>Manifest</code> module.</p>
                     </release-item>
 
+                    <release-item>
+                        <p>No longer run <id>master</id> branch through CI. The <id>integration</id> branch will be run through CI and then pushed to <id>master</id> with github status checks.</p>
+                    </release-item>
+
                     <release-item>
                         <p>Move restore test infrastructure to <code>HostBackup.pm</code>.  Required to test restores on the backup server, a fairly common scenario.  Improve the restore function to accept optional parameters rather than a long list of parameters. In passing, clean up extraneous use of <code>strType</code> and <code>strComment</code> variables.</p>
                     </release-item>

test/lib/pgBackRestTest/Common/CiTest.pm

@@ -74,7 +74,6 @@ sub process
     my $strConfig =
         "branches:\n" .
         "  only:\n" .
-        "    - master\n" .
         "    - integration\n" .
         "    - /-ci\$/\n" .
         "\n" .