Custom certs per role

- Upload the cert with `sshkit.upload!`
- Use the role name to create a directory for each role's certs
- Add an integration test for the custom certs

test/integration/docker/deployer/app_with_custom_certificate/certs/cert.pem

@@ -0,0 +1,19 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

test/integration/docker/deployer/app_with_custom_certificate/certs/key.pem

@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----