Manual nim builds work fine but installing choosenim fails
Hello,

I can build nim manually using [this script][1]. 

I still I wanted to see what `choosenim` looked like, but I am unable to install it. It fails with this error:

```
> curl https://nim-lang.org/choosenim/init.sh -sSf | sh
choosenim-init: Downloading choosenim-0.2.2_linux_amd64
/tmp/choosenim-0.2.2_linux_amd64: /lib64/libc.so.6: version `GLIBC_2.14' not found (required by /tmp/choosenim-0.2.2_linux_amd64)
/tmp/choosenim-0.2.2_linux_amd64: /lib64/libc.so.6: version `GLIBC_2.15' not found (required by /tmp/choosenim-0.2.2_linux_amd64)
```

I am using RHEL 6.6.

Is that dependency failure for building `choosenim` or `nim`?

[1]: https://gist.github.com/261ba46487cbea9c6ad10c62ca2ee3e8