Include drone.bat to run Windows tests

.drone/drone.bat

@@ -0,0 +1,31 @@
+
+@ECHO ON
+setlocal enabledelayedexpansion
+
+if "%DRONE_JOB_BUILDTYPE%" == "boost" (
+
+echo '==================================> INSTALL'
+
+git clone https://github.com/boostorg/boost-ci.git boost-ci-cloned --depth 1
+cp -prf boost-ci-cloned/ci .
+rm -rf boost-ci-cloned
+REM source ci/travis/install.sh
+REM The contents of install.sh below:
+
+for /F %%i in ("%DRONE_REPO%") do @set SELF=%%~nxi
+SET BOOST_CI_TARGET_BRANCH=%DRONE_COMMIT_BRANCH%
+SET BOOST_CI_SRC_FOLDER=%cd%
+
+call ci\common_install.bat
+
+echo '==================================> COMPILE'
+
+REM set B2_TARGETS=libs/!SELF!/test libs/!SELF!/example
+set B2_TARGETS=libs/!SELF!/test
+call !BOOST_ROOT!\libs\!SELF!\ci\build.bat
+
+) else if "%DRONE_JOB_BUILDTYPE%" == "standalone-windows" (
+
+REM not used
+
+)