Fixes segfault caused by accessing destroyed logging object when test file is successfully removed.
Wrap test file removal with non-fatal test assertion.
Merge pull request #19 from BSMaidSafe/MAID-259_RoutingNetworkTest_Segfault

Fixes segfault caused by accessing destroyed logging object when test fi...
Merge remote-tracking branch 'upstream/next' into MAID-193_RoutingTableTest.BEH_GetNthClosest