Merge pull request #6960 from emmanuelsearch/delete-3des

sys/crypto/3des.c

sys/crypto/doc.txt

sys/include/crypto/3des.h

sys/include/crypto/ciphers.h

tests/unittests/tests-crypto/tests-crypto-3des.c

tests/unittests/tests-crypto/tests-crypto.c

tests/unittests/tests-crypto/tests-crypto.h