Try codecov for code coverage

.travis.yml

@@ -52,6 +52,13 @@ matrix:
     - os: linux
       compiler: clang
       env: CLANG_VERSION='3.8.0' BUILDTYPE=Debug CC="clang-3.8" CXX="clang++-3.8" CXXFLAGS="--coverage" CFLAGS="--coverage" LDFLAGS="--coverage"
+      after_script:
+        - mason install llvm-cov 3.9.1
+        - mason link llvm-cov 3.9.1
+        - which llvm-cov
+        - curl -S -f https://codecov.io/bash -o codecov
+        - chmod +x codecov
+        - ./codecov -x "llvm-cov gcov" -Z
       addons:
         apt:
           sources: ['ubuntu-toolchain-r-test' ]
@@ -101,8 +108,3 @@ script:
        BUILDTYPE=${BUILDTYPE} make fewer-tests; else
        BUILDTYPE=${BUILDTYPE} make test geobuf-test;
    fi
- - if [ -n "${COVERAGE}" ]; then
-       /usr/bin/llvm-cov-3.5 -lp *.o;
-       pip install --user cpp-coveralls;
-       ~/.local/bin/coveralls --no-gcov -i ./ --exclude catch --exclude jsonpull --exclude mapbox --exclude milo --exclude protozero ;
-   fi