geckodriver: drop unused versions

component/firefox/buildout.cfg

@@ -207,36 +207,12 @@ version = 0.22.0
 i686-md5sum = 6de7544753fda56fbaa8382dcac99aaa
 x86_64-md5sum = 81746200ce5841e00cabf3b8ea7db542
 
-[geckodriver-0.21.0]
-<= geckodriver-base
-version = 0.21.0
-i686-md5sum = 9fc1657dd1b94272d0cdb3b29ca80f79
-x86_64-md5sum = 6bc36d4fd4975e296cdb3fa3c5e26a41
-
-[geckodriver-0.19.0]
-<= geckodriver-base
-version = 0.19.0
-i686-md5sum = 07cd383c8aef8ea5ef194a506141afd6
-x86_64-md5sum = ca6935a72fd0527d15a78a17a35e56e8
-
-[geckodriver-0.17.0]
-<= geckodriver-base
-version = 0.17.0
-i686-md5sum = 79b1a158f96d29942a111c0905f1c807
-x86_64-md5sum = be18faeea6e7db9db6990d8667e2298f
-
 [geckodriver-0.16.1]
 <= geckodriver-base
 version = 0.16.1
 i686-md5sum = not not on github
 x86_64-md5sum = 57dfd55d4759d9878eb75b4c0123d00c
 
-[geckodriver-0.14.0]
-<= geckodriver-base
-version = 0.14.0
-i686-md5sum = b5836f5a944fe9f3ed1a67c7b342c6a7
-x86_64-md5sum = 4a185d3179862a35104603b9274452e7
-
 
 [geckodriver-base]
 # Installs geckodriver ${version}