get directories right

tools/run_tests/run_tests.py

@@ -478,7 +478,7 @@ if len(build_configs) > 1:
 if platform.system() == 'Windows':
   def make_jobspec(cfg, targets):
     return [
-      jobset.JobSpec(['msbuild.exe', 
+      jobset.JobSpec(['vsprojects\\build.bat', 
                       'vsprojects\\%s.sln' % target, 
                       '/m',
                       '/p:Configuration=%s' % _WINDOWS_CONFIG[cfg]],

vsprojects/build.bat

@@ -0,0 +1,10 @@
+@rem Convenience wrapper that runs specified gRPC target using msbuild
+@rem Usage: build.bat TARGET_NAME
+
+setlocal
+@rem Set VS variables (uses Visual Studio 2013)
+@call "%VS120COMNTOOLS%\..\..\vc\vcvarsall.bat" x86
+
+msbuild %*
+exit /b %ERRORLEVEL%
+endlocal