test fix

Author: kcotto

.travis.yml

@@ -5,7 +5,7 @@ compiler:
     - gcc
 
 before_script:
-    - if [ "$TRAVIS_OS_NAME" == "osx" ]; then (brew install lcov); fi
+    - if [ "$TRAVIS_OS_NAME" == "osx" ]; then (brew update && brew install lcov); fi
     - gem install coveralls-lcov
 
 script:
@@ -23,6 +23,10 @@ os:
     - linux
     - osx
 
+jobs:
+    include:
+        - osx_image: xcode12.5
+
 notifications:
     email:
         on_failure: always