Making it so reservation compiles with an empty local m2 repo

This seems to be an analog of bug 1656 in the TTP repo. Basically, the
nexusproxy variable isn't resolved when maven tries to resolve the parent,
which results in it being unable to fetch odlparent from the
opendaylight-snapshot repository. This fixes that by expanding the URL.

Change-Id: I10ea9a5a117178c744ea87645ac3a1230a290e96
Signed-off-by: Colin Dixon <colin@colindixon.com>
Merge "Making it so reservation compiles with an empty local m2 repo"