cs always fails

cs always fails.

ex)

```
$ cs foundweekends/giter8
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.jboss.netty.util.internal.ByteBufferUtil (file:/Users/hirose/.conscript/boot/scala-2.11.12/org.foundweekends.conscript/conscript/0.5.3/netty-3.9.2.Final.jar) to method java.nio.DirectByteBuffer.cleaner()
WARNING: Please consider reporting this to the maintainers of org.jboss.netty.util.internal.ByteBufferUtil
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
An unexpected error occurred: Please check your internet connection.
Exception message: https://api.github.com/repos/foundweekends/giter8/git/refs/heads/master
```

setup also fails.

```
cs --setup
```