Fixes the deletion of the target directory after installation

[anpieber]

Looking into the documentation of the grunt-bower-task we read:

options.cleanTargetDir: Will clean target dir BEFORE running install.
options.cleanBowerDir: Will remove bower's dir AFTER copying all needed files into target dir.

Therefore, what we really want is cleanTargetDir instead of
cleanBowerDir

[searls]

I believe I intentionally was deleting bower's directory and leaving the target one. Something something at this point source control gave up and all six of us working on this just said (╯°□°）╯︵ ┻━┻

@jasonkarns can you remember how this was supposed to be (as it pertains to this issue)?

[jasonkarns]

I believe @searls is correct. Initially, in github-notifications, the bower directory was configured using the directory option in .bowerrc. This was changed in searls/github-notifications@1152a93 so that the bower directory was configured using the grunt-bower-task. However, the grunt-bower-task targetDir configuration option isn't a direct replacement for directory in .bowerrc. Most notably, components are still downloaded under bower_components, and grunt-bower-task simply copies them to targetDir. So, in order to get the behavior most similar to using directory in .bowerrc, the bower directory is deleted by grunt-bower-task (using options.cleanBowerDir). That is, components appear to be downloaded directly to vendor/bower. Of course, since bower itself is not actually aware of vendor/bower, then the components are re-downloaded each time grunt-bower-task triggers a bower install, which is obviously sub-optimal.

There is an open PR to grunt-bower-task to really make targetDir the real target location for bower components; as if it were set in .bowerrc. Until it is merged, options.cleanBowerDir will still be necessary.

If you're looking for a way to clean the target directory (vendor/bower), that is accomplished by lineman clean:bower (as configured here).