mitigate 5.2 failure

Author: ashnazg

.travis.yml

@@ -21,7 +21,7 @@ matrix:
   - php: 7.3
     dist: trusty
 install:
-  - pear upgrade --force --alldeps pear/pear
+  - pear upgrade --force --alldeps pear/pear || true
   - pear install -f package.xml
 script:
   - pear run-tests -qr tests/