upgrade codecov config

- https://docs.codecov.io/docs
- https://github.com/codecov/example-java-maven
- https://github.com/codecov/example-kotlin

.travis.yml

@@ -29,7 +29,6 @@ before_install:
   - ls -l /usr/lib/jvm && ls /usr/lib/jvm/*
   - echo -e "JAVA_HOME=$JAVA_HOME\nPATH=$PATH"
   - ./mvnw --version
-  - pip install --user codecov
 
 script:
   # default Java 8, do build and test
@@ -47,9 +46,13 @@ script:
   - jdk_switcher use oraclejdk9
   - ./scritps/run-junit.sh skipClean
   - ./scritps/run-agent-test.sh skipClean
+  # codecov
+  - jdk_switcher use oraclejdk8
+  - mvn clean -V
+  - mvn cobertura:cobertura
 
 after_success:
-  - codecov
+  - bash <(curl -s https://codecov.io/bash)
 
 # cache between builds
 cache: