Group patches to phishing warning page under the same minor version

As Lego noted in #79, we lack the ability to perform on the fly patch updates to the phishing warning page used by the MetaMask extension. This is due to the fact that we pin MetaMask to point to a specific `x.y.z` version of the phishing warning page. The only way we change this now is through updating the phishing warning page package used by MetaMask.

However, if we begin to make phishing warning page releases exist under a minor version granularity (ex: `v1.2.4` publishes to `metamask.github.io/phishing-warning/v1.2`), we can automatically have updates stream live to all MetaMask extension users who have their update configured to `v1.2`.

An argument could be made to extend this to major version so that all non-breaking changes can be propagated automatically