修复背包问题BUG
Merge branch 'master' of
https://github.com/zhanghao-py/algorithms_bjut.git

Conflicts:
	src/main/java/cn/edu/bjut/sse/algorithm/dynamicplan/knapsack/KnapsackProblem.java
	src/test/java/cn/edu/bjut/sse/algorithm/dynamicplan/knapsack/KnapsackTest.java