Update .gitignore and test directory generator

Author: mdmintz

.gitignore

@@ -72,6 +72,7 @@ geckodriver
 msedgedriver
 operadriver
 MicrosoftWebDriver.exe
+headless_ie_selenium.exe
 IEDriverServer.exe
 chromedriver.exe
 geckodriver.exe

seleniumbase/console_scripts/sb_mkdir.py

@@ -241,6 +241,7 @@ def main():
     data.append("msedgedriver")
     data.append("operadriver")
     data.append("MicrosoftWebDriver.exe")
+    data.append("headless_ie_selenium.exe")
     data.append("IEDriverServer.exe")
     data.append("chromedriver.exe")
     data.append("geckodriver.exe")