Add DDS and DVM Suffixes

[HaroldPutman]

There is a never-ending stream of professional suffixes, but these two in particular are used in Faker but aren't currently supported here.

[coveralls]

Coverage remained the same at 100.0% when pulling 9a62b31 on HaroldPutman:faker-suffixes into e40c25b on theiconic:master.

[HaroldPutman]

While looking into #42 I discovered that it is not hard to add domain-specific professional suffixes or salutations. But I still think these should be added since a new user who creates a Laravel factory and throws fake names against the out-of-the box parser might worry that this doesn't work well.

[wyrfel]

Thanks @HaroldPutman