Removing Gemfile.lock
Editing the '--sdk' Command

When the '--sdk' command was added to the list of options with a short
flag of '-sdk', the '-s' flag for the scheme option was been
overridden. It seems as though the options parser only took the first
letter for the short option flag and discarded the rest.
Only Perform Configuration Check if Project is Defined

The 'xcodebuild -list' command will not list out configurations for
workspaces, which causes the configuration validation to fail. With
this change, if you're building a workspace, xcodebuild will use the
default configuration (seems to be Release, which should be fine).
However, you can still specify Debug in the ipa options and it will
adhere to them.