add pip check back into the recipe

Author: varlackc

recipe/meta.yaml

@@ -31,13 +31,16 @@ requirements:
 test:
   imports:
     - pybind11
+  requires:
+    - pip
   commands:
     - test -f ${PREFIX}/share/cmake/pybind11/pybind11Config.cmake                                     # [unix]
     - if exist %LIBRARY_PREFIX%\share\cmake\pybind11\pybind11Config.cmake (exit 0) else (exit 1)      # [win]
     - test -f ${PREFIX}/include/pybind11/pybind11.h      # [unix]
     - if exist %LIBRARY_INC%\pybind11\pybind11.h (exit 0) else (exit 1)      # [win]
     - test -f $(python -c "import pybind11 as py; print(py.get_include())")/pybind11/pybind11.h      # [unix]
     - if exist $(python -c "import pybind11 as py; print(py.get_include())")\pybind11\pybind11.h (exit 0) else (exit 1)      # [win]
+    - pip check
 
 about:
   home: https://github.com/pybind/pybind11/