Add valgrind tests on Travis

.travis.yml

@@ -3,6 +3,10 @@ compiler:
 - clang
 - gcc
 sudo: false
+addons:
+  apt:
+    packages:
+    - valgrind
 script:
 - tests/scripts/recursion.pl library/*.c
 - tests/scripts/check-generated-files.sh
@@ -16,6 +20,9 @@ script:
 - tests/ssl-opt.sh -e '\(DTLS\|SCSV\).*openssl'
 - tests/scripts/test-ref-configs.pl
 - tests/scripts/curves.pl
+- make
+- make memcheck
+- tests/ssl-opt.sh -e '\(DTLS\|SCSV\).*openssl' --memcheck
 env:
   global:
     secure: "barHldniAfXyoWOD/vcO+E6/Xm4fmcaUoC9BeKW+LwsHqlDMLvugaJnmLXkSpkbYhVL61Hzf3bo0KPJn88AFc5Rkf8oYHPjH4adMnVXkf3B9ghHCgznqHsAH3choo6tnPxaFgOwOYmLGb382nQxfE5lUdvnM/W/psQjWt66A1+k="