added link to blog post on reducing size of Docker images
added link to blog post on reducing size of Docker images

ChrisTimperley/RepairBox,ChrisTimperley/RepairBox,ChrisTimperley/AutomatedRepairBenchmarks.c,squaresLab/RepairBox,ChrisTimperley/RepairBox,ChrisTimperley/AutomatedRepairBenchmarks.c,ChrisTimperley/AutomatedRepairBenchmarks.c,ChrisTimperley/AutomatedRepairBenchmarks.c,ChrisTimperley/AutomatedRepairBenchmarks.c,ChrisTimperley/AutomatedRepairBenchmarks.c,ChrisTimperley/RepairBox,ChrisTimperley/RepairBox,ChrisTimperley/AutomatedRepairBenchmarks.c,ChrisTimperley/RepairBox,ChrisTimperley/RepairBox,ChrisTimperley/AutomatedRepairBenchmarks.c,ChrisTimperley/RepairBox,ChrisTimperley/RepairBox,ChrisTimperley/AutomatedRepairBenchmarks.c,ChrisTimperley/RepairBox