convert unit_tests/compile (#1517)

unit_tests/compile.bat

@@ -1,4 +1,8 @@
-echo I am compiling unit tests
-rm -rf .dep/
-rm -rf build/
-make -j4
+@echo off
+sh.exe compile.sh || (
+  if exist C:\cygwin64 (
+    C:\cygwin64\bin\sh.exe compile.sh
+  ) else (
+    if exist C:\cygwin ( C:\cygwin\bin\sh.exe compile.sh )
+  )
+)

unit_tests/compile.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+echo "Compiling unit tests"
+rm -rf .dep/
+rm -rf build/
+make -j4