A change was recently made to npm’s infrastructure that caused many users to receive a
SELF_SIGNED_CERT_IN_CHAIN error during installation and publishing of packages. The npm-recommended fix is to set a blank value for
ca in your npm config.
This issue can be circumvented by upgrading to node
0.10.26 or greater, but the upgrade is not required. The node buildpack has been updated to automatically generate an
.npmrc for your app with the blank
ca entry, if one is not already present.