Explicitly run markdown-toc with bash on Windows

runtests

@@ -4,6 +4,7 @@ from __future__ import print_function
 import argparse
 import glob
 import os
+import platform
 import shutil
 import sys
 import tempfile
@@ -11,6 +12,7 @@ import tempfile
 from subprocess import check_call, check_output
 
 
+_WINDOWS = platform.system().lower() == 'windows'
 _PACKAGE_NAME = os.environ.get(
     'CLI_PACKAGE_NAME', 'github.com/urfave/cli'
 )
@@ -94,8 +96,9 @@ def _migrations():
 
 @_target
 def _toc():
-    _run([
+    exe = ['bash'] if _WINDOWS else []
-        'node', os.path.join('node_modules', '.bin', 'markdown-toc'),
+    _run(exe + [
+        os.path.join('node_modules', '.bin', 'markdown-toc'),
         '-i', 'README.md'
     ])
     _run(['git', 'diff', '--quiet'])