Fix windows include on mingw-w64 (#182)
diff --git a/test/main-override.cc b/test/main-override.cc
index fa84b63..0323ff6 100644
--- a/test/main-override.cc
+++ b/test/main-override.cc
@@ -139,7 +139,7 @@
#endif
#ifdef _WIN32
-#include <Windows.h>
+#include <windows.h>
static void
test_initialize(void) {
diff --git a/test/main.c b/test/main.c
index 6d6b323..805cbec 100644
--- a/test/main.c
+++ b/test/main.c
@@ -1100,7 +1100,7 @@
#endif
#ifdef _WIN32
-#include <Windows.h>
+#include <windows.h>
static void
test_initialize(void) {
diff --git a/test/thread.c b/test/thread.c
index 5e3ad8d..adaab44 100644
--- a/test/thread.c
+++ b/test/thread.c
@@ -8,7 +8,7 @@
#endif
#ifdef _WIN32
-# include <Windows.h>
+# include <windows.h>
# include <process.h>
static unsigned __stdcall