Smoke test railing binary

See e.g. failure at https://github.com/cloudozer/ling/pull/23#issuecomment-68250747
Merge pull request #24 from lucafavatella/ci-test-railing

Smoke test railing binary on Travis CI
Supply instance of `hibernate` call to instructions analysis script...

... in order to prevent `unused-label` warning when compiling the
generated `ling_main.c`.

Both `kernel` and `stdlib` OTP apps contain calls to `hibernate`:
```
$ git grep erlang:hibernate OTP-17.4 -- lib/*/src
OTP-17.4:lib/kernel/src/rpc.erl:261:        erlang:hibernate(?MODULE, proxy_user_flush, [])
OTP-17.4:lib/stdlib/src/proc_lib.erl:205:    erlang:hibernate(?MODULE, wake_up, [M, F, A]).
```

I supply module `proc_lib` (in app `stdlib`) rather than `rpc` (in app
`kernel`) as in `proc_lib` the usage of `hibernate` looks less prone
to changes.

Addresses https://github.com/cloudozer/ling/pull/23#issuecomment-68249112
Merge pull request #25 from lucafavatella/hibernate

Supply instance of `hibernate` call to instructions analysis script