Update `inflection` dependency to v1.5.3

This PR updates inflection dependency to the newly-released v1.5.3 which corrects several errors in not pluralizing words which should be pluralizable. (see https://github.com/dreamerslab/node.inflection/pull/33)

The behaviour in 1.5.2 which I found most irritating was that it would not pluralize "permission" to "permissions" meaning that my Sequelize model `permission` had its table called `permission` too. Argh!