fix build on iOS 7.1+

iPhoneSimulatorRemoteClient.framework was renamed to DVTiPhoneSimulatorRemoteClient on the latest iOS - when trying to install xctool, I got this:

```
=== BUILD TARGET xctool OF PROJECT xctool WITH CONFIGURATION Release ===

Check dependencies

Ld /usr/local/Cellar/xctool/HEAD/libexec/bin/xctool normal x86_64
    cd /Library/Caches/Homebrew/xctool--git/xctool
    export MACOSX_DEPLOYMENT_TARGET=10.7
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk -L/Library/Caches/Homebrew/xctool--git/build/dc4b35f/Products/Release -F/Library/Caches/Homebrew/xctool--git/build/dc4b35f/Products/Release -F/Applications/Xcode.app/Contents/Developer/Library/Frameworks -F/Library/Caches/Homebrew/xctool--git/xctool/../Vendor -filelist /Library/Caches/Homebrew/xctool--git/build/dc4b35f/Intermediates/xctool.build/Release/xctool.build/Objects-normal/x86_64/xctool.LinkFileList -mmacosx-version-min=10.7 -F/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Library/PrivateFrameworks -weak_framework iPhoneSimulatorRemoteClient -fobjc-link-runtime -stdlib=libc++ -framework QuartzCore -framework Foundation -Xlinker -dependency_info -Xlinker /Library/Caches/Homebrew/xctool--git/build/dc4b35f/Intermediates/xctool.build/Release/xctool.build/Objects-normal/x86_64/xctool_dependency_info.dat -o /usr/local/Cellar/xctool/HEAD/libexec/bin/xctool
ld: framework not found iPhoneSimulatorRemoteClient
clang: error: linker command failed with exit code 1 (use -v to see invocation)
```

Fixing the framework name fixes that and it builds fine.