Travis: when showing a log fails, keep trying to show other logs

When a Travis build fails, and showing a log fails, keep trying to
show the other logs.

Fixes bug 27453; bugfix on 0.3.4.7-rc.

.travis.yml

@@ -143,11 +143,11 @@ script:
 after_failure:
   ## configure will leave a log file with more details of config failures.
   ## But the log is too long for travis' rendered view, so tail it.
-  - tail -1000 config.log
+  - tail -1000 config.log || echo "tail failed"
   ## `make check` will leave a log file with more details of test failures.
-  - if [[ "$DISTCHECK" == "" ]]; then cat test-suite.log; fi
+  - if [[ "$DISTCHECK" == "" ]]; then cat test-suite.log || echo "cat failed"; fi
   ## `make distcheck` puts it somewhere different.
-  - if [[ "$DISTCHECK" != "" ]]; then make show-distdir-testlog; fi
+  - if [[ "$DISTCHECK" != "" ]]; then make show-distdir-testlog || echo "make failed"; fi
 
 after_success:
   ## If this build was one that produced coverage, upload it.

changes/bug27453

@@ -0,0 +1,3 @@
+  o Minor bugfixes (continuous integration):
+    - When a Travis build fails, and showing a log fails, keep trying to
+      show the other logs. Fixes bug 27453; bugfix on 0.3.4.7-rc.