ensime is not a dependency of scala-mode

[davidshen84]

I tried to install scala-mode from MELPA. But I got:

Entering directory `/home/david/.emacs.d/elpa/scala-mode-20160813.304/'
ob-scala.el:27:1:Error: Cannot open load file: no such file or directory, ensime

I have manually install ensime package before installing scala-mode.

My Emacs version is GNU Emacs 24.5.1 (x86_64-unknown-cygwin)

[hvesalai]

@reactormonk, @fommil requiring ensime from ob-scala.el should be done so that it fails quietly if ensime it is not present.

(require FEATURE &optional FILENAME NOERROR), i.e. (require ensime "ensime" t)

[reactormonk]

All functionality of this ob-scala depends on ensime. The logic that doesn't hasn't been merged yet.

[fommil]

I understand this is all going to be moved into org mode at some point anyway by @reactormonk and merged with the existing impl (turns out they already had one)

[fommil]

#114