add 'rake all' for all specs (core and services)

Signed-off-by: Jing Gong <jgong@rbcon.com>
remove unneccessary require

Signed-off-by: Jing Gong <jgong@rbcon.com>
update README.md; update rake service task to include services_spec cases

Signed-off-by: Jing Gong <jgong@rbcon.com>
Merge branch 'master' of github.com:jgong/vcap-yeti