Update dist_install test to work around Python issue
Update dist_install test to work around Python issue

googletest uses a Python script in its build which is not compatible
with Python 3. Unfortunately we can't easily upgrade googletest right
now, so this commit works around the problem by putting a python symlink
pointing to Python 2 in the $PATH.

google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf