Attempt to un-break Appveyor:

- Put '_testing' on PYTHONPATH only for Py3k (debug grpico-on-Py3k issues
  later).

- Use 'setup.py develop' rather than 'setup.py build' to get dependencies
  installed.

- Run 'pip list' afterwards to show what got installed.

Toward #1863.

appveyor.yml

@@ -30,21 +30,29 @@ environment:
  - PYTHON: "C:\\Python34"
  PYTHON_VERSION: "3.4.4"
  PYTHON_ARCH: "32"
+ # Use mocked-up GRPC for now
+ GRPC_PATH: "_testing"
 
  - PYTHON: "C:\\Python34-x64"
  PYTHON_VERSION: "3.4.4"
  PYTHON_ARCH: "64"
+ # Use mocked-up GRPC for now
+ GRPC_PATH: "_testing"
 
  # Python 3.5.1 is the latest Python 3.5 with a Windows installer
  # Python 3.5.1 is the overall latest
  # https://www.python.org/ftp/python/3.5.1/
  - PYTHON: "C:\\Python35"
  PYTHON_VERSION: "3.5.1"
  PYTHON_ARCH: "32"
+ # Use mocked-up GRPC for now
+ GRPC_PATH: "_testing"
 
  - PYTHON: "C:\\Python35-x64"
  PYTHON_VERSION: "3.5.1"
  PYTHON_ARCH: "64"
+ # Use mocked-up GRPC for now
+ GRPC_PATH: "_testing"
 
 install:
  - ECHO "Filesystem root:"
@@ -78,10 +86,12 @@ install:
 
 build_script:
  # Build the compiled extension
- - "%CMD_IN_ENV% python setup.py build"
+ #- "%CMD_IN_ENV% python setup.py build"
+ - "%CMD_IN_ENV% python setup.py develop"
+ - "%CMD_IN_ENV% pip list"
 
 test_script:
- - "set PYTHONPATH=_testing"
+ - "set PYTHONPATH=%GRPC_PATH%"
  # Run the project tests
  - "%CMD_IN_ENV% python setup.py nosetests"