[REBUILD] Fix cached dist builds breaking travis statuses

The check for whether .travis.yml file exists happens only when dist has new commits. Lacking those, the site thinks .travis.yml file was removed and the dist is not setup on travis, so it tosses the cached travis status too. (Closes #50)

lib/ModulesPerl6/DbBuilder/Dist/Source/GitHub.pm

@@ -80,8 +80,11 @@ sub load {
     } // 0;
 
     # no new commits and we have cached results that will do just fine
-    return $dist
-        if $dist->{date_updated} eq $date_updated and not $ENV{FULL_REBUILD};
+    if ( $dist->{date_updated} eq $date_updated and not $ENV{FULL_REBUILD} ) {
+        $dist->{_builder}{has_travis} = 1 # reinstate cached travis status
+            unless $dist->{travis_status} eq 'not set up';
+        return;
+    }
     $dist->{date_updated} = $date_updated;
 
     log info => 'Dist has new commits. Fetching more info.';
@@ -102,7 +105,6 @@ sub load {
     delete $dist->{koalatee};
     $self->_set_readme( map $_->{path}, grep $_->{type} eq 'blob', @$tree );
     $self->_set_tests(  map $_->{path}, grep $_->{type} eq 'tree', @$tree );
-
     $dist->{_builder}{has_travis} = grep $_->{path} eq '.travis.yml', @$tree;
 
     return $dist;