Investigate long build times

If I pip install couchbase, it takes a very long time (on my Mac) to build.   Seems like it is way longer than when I rm rf build/ ; python3 setup.py build_ext -inplace

That strikes me as odd – but then again I've not actually timed it. Lets confirm that, and if so, look at why it may be. We should see the pip install take roughly same time as the setup.py (with an empty build directory). If it is significantly longer, let's look at what we are doing (setup.py, our CMakeList.txt, etc...). If not, then perhaps best to close this as integrating txn and client, for instance, may change things.