fix(install): make sure to reload explicitRequests

when we are placing our deps, if our edge dep was explicitly requested,
we want to re-place it instead of leaving whatever was there before.

This will mean doing something like `npm install foo` will install the
latest version of `foo` that your tree currently allows, instead of
doing nothing if any version already existed

lib/arborist/build-ideal-tree.js

@@ -1094,6 +1094,7 @@ This is a one-time fix-up, please be patient...
   [_placeDep] (dep, node, edge, peerEntryEdge = null, peerPath = []) {
     if (edge.to &&
         !edge.error &&
+        !this[_explicitRequests].has(edge.name) &&
         !this[_updateNames].includes(edge.name) &&
         !this[_isVulnerable](edge.to))
       return []