Add bob-walker in Scala

Initial commit. Not incredibly idiomatic Scala and doesn't have everything implemented, but it's a start.
These can all be done on one line
Clarify this step

I thought there would be a better way to do this but Dave told me that it is idiomatic just to leave it, or put a comment saying `do nothing` (as I had previously), but I expanded this comment just to clarify for those unfamiliar with Scala.
Use camel case not snake case

As is idiomatic for Scala.

Also, no need for this to be a case class as it doesn't store data, and no need for it to be final, really.
Change most Arrays to Seqs

It is more idiomatic in Scala to use Seqs; Arrays are rarely used. The Array in the main method definition however cannot be changed as that is in the main method signature.
Fix bug whereby it requires CLI args

Previous version printed out nothing if you passed no parameters, whereas bob walker with no paramters should print out beard, beer and pie. This commit fixes that.
Add haskell version

Feels like I cheated by using unsafePerformIO :(

To play with:

```
$ ghc -o bob-walker bob-walker.hs
```
Move modes into for comprehension

The calculation of which modes should be added for a flag can be inside the for comprehension.
Extract characters from args in for comprehension
Replace while loop with for comprehension
Add Scala to README
Merge pull request #21 from annashipman/scala-bob

Scala bob
Merge pull request #19 from jabley/haskell-bob

Add haskell version
Erlang (script) bob

Implement bob in Erlang. Using escript because it's easier to run and parse
CLI arguments. Supports drunk, sport, programming, and xmas modes. Doesn't
support short CLI arguments.
Alphabetise Erlang entry in README

Because OCD people.
Erlang sleep between words when drunk

To match the Perl implementation. I've opted for a function with a different
argument signature rather than specifying a sleep duration of 0 and always
calling timer:sleep.
Merge pull request #22 from dcarley/erlang_script

Erlang (script) bob