Fix in clearing space fields of config data on cf space-delete

Before Fix: If cf user deleting the targeted space but with space name as
case insenstive then space fields are not deleted from the config
htipl@cf5:~/go/src/github.com/cloudfoundry/cli$ cf spaces
Getting spaces in org SriniOrg as admin...
name
No spaces found
htipl@cf5:~/go/src/github.com/cloudfoundry/cli$ cf target
API endpoint:   https://api.10.244.0.34.xip.io (API version: 2.13.0)
User:           admin
Org:            SriniOrg
Space:          SriniSpace

After Fix:If cf user does same steps
space fields are deleted from the config
htipl@cf5:~/go/src/github.com/cloudfoundry/cli$ ./out/cf spaces
Getting spaces in org SriniOrg as admin...
name
No spaces found
htipl@cf5:~/go/src/github.com/cloudfoundry/cli$ ./out/cf target
API endpoint:   https://api.10.244.0.34.xip.io (API version: 2.13.0)
User:           admin
Org:            SriniOrg
Space:          No space targeted, use 'cf target -s SPACE'

http://rnd-github.huawei.com/paas/cli/issues/28
plugin fixture for alias conflict tests

[#83717740]
`cf install-plugin` cross-checks for command/alias conflicts

[#83717740]
improve error text for plugin alias conflict errors.

[finishes #83717740]
update confusing code comment
plugin alias shows in `cf help`

[finishes #83892240]

Signed-off-by: Jonathan Berkhahn <jaberkha@us.ibm.com>
`cf plugins` shows command alias

[finishes #83892154]
unfocus plugin test
Add unset flag to `cf api`

-Allows user to unset the api endpoint

[#82979408]

Signed-off-by: Cristovao Dutra <cristovaodoj@gmail.com>
Add dashboard-url to `cf service` output

[#68396596]

Signed-off-by: Cristovao Dutra <cristovaodoj@gmail.com>
Add `cf restart_app_instance` command

[#78049908]

Signed-off-by: Simon Leung <leungs@us.ibm.com>
Update ginkgo

Signed-off-by: Simon Leung <leungs@us.ibm.com>
create-buildpack and update-buildpack now allow relative paths.

Finishes [#80043644]
remove incorrect comment in test fixtures
New utils for download single file from url
Exit non-zero in build-and-release-gocd if sub-script fails

Signed-off-by: Simon Leung <leungs@us.ibm.com>
test fix and additional coverage

[#80043644]

Signed-off-by: Jonathan Berkhahn <jaberkha@us.ibm.com>
Remove commented line in update_service_test

Signed-off-by: Derek Richard <drichard@pivotal.io>
Allows mutliple plugins with blank aliases.

[Finishes #84241752]

Signed-off-by: Simon Leung <leungs@us.ibm.com>
Allows plugin to be installed from an Url

[finishes #80043644]

Signed-off-by: Jonathan Berkhahn <jaberkha@us.ibm.com>