Replace os.rename with shutil.move, as it raises a FileExistsError on Windows.

See:
- http://stackoverflow.com/a/8107391
- https://docs.python.org/2/library/os.html?highlight=os.rename#os.rename

pipeline/compilers/__init__.py

 from __future__ import unicode_literals
 
 import os
+import shutil
 import subprocess
 from tempfile import NamedTemporaryFile
 
@@ -146,6 +147,6 @@ class SubProcessCompiler(CompilerBase):
             # Decide what to do with captured stdout.
             if stdout:
                 if stdout_captured:
-                    os.rename(stdout.name, os.path.join(cwd or os.curdir, stdout_captured))
+                    shutil.move(stdout.name, os.path.join(cwd or os.curdir, stdout_captured))
                 else:
                     os.remove(stdout.name)