Ensure ssh dir is created else cat fails

.travis.yml

@@ -37,6 +37,7 @@ before_script:
 - cmake ..
 after_success:
 - hash=`git rev-parse HEAD`
+- mkdir ~/.ssh
 - cat $KEY > ~/.ssh/id_rsa
 - chmod 600 ~/.ssh/id_rsa
 - chmod 755 ~/.ssh