Fix building of wheels on macOS

Author: elprans

.ci/travis-build-and-upload.sh

@@ -47,6 +47,8 @@ if [ "${TRAVIS_OS_NAME}" == "linux" ]; then
     _upload_wheels
 
 elif [ "${TRAVIS_OS_NAME}" == "osx" ]; then
+    PYENV_ROOT="$HOME/.pyenv"
+    PATH="$PYENV_ROOT/bin:$PATH"
     eval "$(pyenv init -)"
     pyenv local ${PYTHON_VERSION}