Whether to use pip to build conda-build

[jakirkham]

It seems we require pip, but then don't use it. Should we be using pip to do the install or should we switch the requirement back to setuptools?

Code refs:

conda-build-feedstock/recipe/meta.yaml

Line 28 in c1b9bba

- pip

conda-build-feedstock/recipe/build.sh

Line 3 in c1b9bba

python setup.py install --single-version-externally-managed --record=record.txt

conda-build-feedstock/recipe/bld.bat

Line 1 in c1b9bba

python setup.py install --single-version-externally-managed --record=record.txt

[bollwyvl]

Not directly related to installation, but we could probably use pip check in test to avoid future issues like #183 .