CI: Provide objective-c environment for iOS build
CI: Provide objective-c environment for iOS build

Don't know the difference, but there is definitely something holding the
configuration script of OpenSSL to find the right compiler (cc instead of gcc)
for Xcode 8.3

zhuhaow/libnekit,zhuhaow/libnekit,zhuhaow/libnekit,zhuhaow/libnekit