Fix windows test failure by closing a file handle before it is removed. Re #2501

Code/Mantid/Framework/DataHandling/test/SaveNISTDATTest.h

@@ -43,7 +43,8 @@ public:
     std::getline( testFile, fileLine );
     TS_ASSERT_EQUALS ( fileLine, "-0.0105  -0.0735  6.13876e+08  6.1697e+07\r" );
 
-    // remove file created by this algorithm
+    // remove file created by this algorithm, closing it first as Windows gets tetchy about this
+    testFile.close();
     Poco::File(outputFile).remove();
   }
 };