Use value instead of DependencyResolution

[mdedetrich]

As explained in #86 it would be ideal to just use the update task in order to retrieve the dependencies from the report however we are blocked by coursier/coursier#1790 (tl;dr coursier doesn't populate license information from ivy.xml descriptor files).

Using Ivy Resolution is also causing other problems, i.e. for dependencies that use packaging.type there is a workaround at sbt/sbt#3618 (comment) however this doesn't seem to work with ivy resolution done by sbt plugins (I think that because of classloader isolation maybe the system properties aren't propogating?)