Move mml-sec.el test data to follow our conventions

* test/lisp/gnus/mml-sec-tests.el (ert-x): Require.
(mml-secure-test-fixture, mml-sec-test--kill-gpg-agent):
Use ert-resource-directory.
* test/lisp/gnus/mml-sec-resources/*: Moved from test/data/mml-sec/.
* .gitignore: Update location of moved file "random_seed".

test/data/mml-sec/gpg-agent.conf

@@ -1,5 +0,0 @@
-# pinentry-program /usr/bin/pinentry-gtk-2
-
-# verbose
-# log-file /tmp/gpg-agent.log
-# debug-all

test/data/mml-sec/trustlist.txt

@@ -1,26 +0,0 @@
-# This is the list of trusted keys.  Comment lines, like this one, as
-# well as empty lines are ignored.  Lines have a length limit but this
-# is not a serious limitation as the format of the entries is fixed and
-# checked by gpg-agent.  A non-comment line starts with optional white
-# space, followed by the SHA-1 fingerpint in hex, followed by a flag
-# which may be one of 'P', 'S' or '*' and optionally followed by a list of
-# other flags.  The fingerprint may be prefixed with a '!' to mark the
-# key as not trusted.  You should give the gpg-agent a HUP or run the
-# command "gpgconf --reload gpg-agent" after changing this file.
-
-
-# Include the default trust list
-include-default
-
-
-# CN=No Expiry
-D0:6A:A1:18:65:3C:C3:8E:9D:0C:AF:56:ED:7A:21:35:E1:58:21:77 S relax
-
-# CN=Second Key Pair
-0E:58:22:9B:80:EE:33:95:9F:F7:18:FE:EF:25:40:2B:47:9D:C6:E2 S relax
-
-# CN=No Expiry two UIDs
-D4:CA:78:E1:47:0B:9F:C2:AE:45:D7:84:64:9B:8C:E6:4E:BB:32:0C S relax
-
-# CN=Different subkeys
-4F:96:2A:B7:F4:76:61:6A:78:3D:72:AA:40:35:D5:9B:5F:88:E9:FC S relax