test: Fix execution of tests from source tree

* Require scikit-build >= 0.7.1 and use skbuild.constants to reference
  CMake binaries.

Author: jcfr

cmake/__init__.py

@@ -12,8 +12,9 @@
 
 # Support running tests from the source tree
 if not os.path.exists(CMAKE_DATA):
+    from skbuild.constants import CMAKE_INSTALL_DIR as SKBUILD_CMAKE_INSTALL_DIR
     _cmake_data = os.path.abspath(os.path.join(
-        os.path.dirname(__file__), '../_skbuild/cmake-install/cmake/data'))
+        os.path.dirname(__file__), '..', SKBUILD_CMAKE_INSTALL_DIR, 'cmake/data'))
     if os.path.exists(_cmake_data):
         CMAKE_DATA = _cmake_data
 

requirements-dev.txt

@@ -5,5 +5,5 @@ pytest>=3.0.3
 pytest-cov>=2.4.0
 pytest-runner>=2.9
 pytest-virtualenv>=1.2.5
-scikit-build>=0.5.0
+scikit-build>=0.7.1
 virtualenv>=15.0.3