cosbench-openio build fails because of unnecessary .classpath definition

[thatsdone]

DESCRIPTION

cosbench-openio build fails saying directory 'test' not found.

REPRODUCE PROCEDURE

Just try to build following BUILD.md, and you would see an error for cosbench-openio.

ANALYSYS and SUGGESTED RESOLUTION

Obviously, this is because dev/cosbench-openio/.classpath contains a classpath element'test' but 'test' directory does not exist.

So, there are 2 resolutions:

1. create dev/cosbench-openio/test
2. remove the classpath element from .classpath

IMHO, 2. is better because there is no test code, and like the case of #413,
a chunk of PR from @Nathaniel7687 resolves this issue.

https://github.com/intel-cloud/cosbench/pull/373/files?file-filters%5B%5D=dotfile&hide-deleted-files=true#diff-79b4a0076c9d63216bc4a7701d85aed387ea2481f854871c83ccabc1d69cf480