Do not reinstall if profile is same and is already installed

Sometimes I have a profile installed and I don't want to re-install it all the time.
Example when using like this

``` ruby
# Buildspec
pprofile_id = '840823DD-B3CC-456A-8F1A-XXX'
pprofile = Xcode::ProvisioningProfile.find_installed_by_uuid(pprofile_id)
puts "Using PProfile: #{pprofile.name} in #{pprofile.path}"
pprofile_path = pprofile.path

group :build do
  use :MyProject, :scheme => :MyScheme
  profile pprofile_path
end
```