Make pip.wheel function take same args as pip.download

src/shiv/cli.py

@@ -90,7 +90,6 @@ def build_wheels(wheel_dir: Path) -> None:
     # build missing wheels
     if to_build:
         pip.wheel(
-            sys.executable,
             ["--wheel-dir", str(wheel_dir), '--find-links', str(wheel_dir)] + to_build,
         )
 

src/shiv/pip.py

@@ -70,14 +70,14 @@ def download(args: List[str]) -> None:
             sys.exit(PIP_DOWNLOAD_ERROR)
 
 
-def wheel(interpreter_path: str, args: List[str]) -> None:
+def wheel(args: List[str]) -> None:
     """`pip wheel` as a function.
 
     Accepts a list of pip arguments.
 
     .. code-block:: py
 
-        >>> wheel('/usr/local/bin/python3', ['numpy', '--wheel-dir', 'site-packages'])
+        >>> wheel(['numpy', '--wheel-dir', 'site-packages'])
         Collecting numpy
         Downloading https://files.pythonhosted.org/packages/8e/75/7a8b7e3c073562563473f2a61bd53e75d0a1f5e2047e576ee61d44113c22/numpy-1.14.3-cp36-cp36m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl (4.7MB)
         Saved ./site-packages/numpy-1.14.3-cp36-cp36m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl
@@ -86,7 +86,7 @@ def wheel(interpreter_path: str, args: List[str]) -> None:
     with clean_pip_env():
 
         process = subprocess.Popen(
-            [interpreter_path, "-m", "pip", "--disable-pip-version-check", "wheel"] + args,
+            [sys.executable, "-m", "pip", "--disable-pip-version-check", "wheel"] + args,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
         )