gsutil ls -lR returns nothing if there is a trailing "/"

for example (and this is an open-access bucket):

```
bash-4.2$ gsutil ls -lR gs://isb-cgc-open/ccle/
0 2016-03-11T17:42:23Z gs://isb-cgc-open/ccle/
TOTAL: 1 objects, 0 bytes (0 B)
```

whereas without the trailing "/" it behaves as expected:

```
bash-4.2$ gsutil ls -lR gs://isb-cgc-open/ccle
gs://isb-cgc-open/ccle/:
0 2016-03-11T17:42:23Z gs://isb-cgc-open/ccle/
12552842 2016-03-11T17:42:23Z gs://isb-cgc-open/ccle/1650_HC_plus_RD_muts.maf.annotated.gz
325803 2016-03-11T17:42:25Z gs://isb-cgc-open/ccle/CCLE_Oncomap3_2012-04-09.maf
66444623 2016-03-11T17:42:25Z gs://isb-cgc-open/ccle/CCLE_expression_CN_muts_GENEE_2010-04-16.gctx

```