Functional tests fails on Travis-ci

[daemon1981]

Functional tests fails if using mocha in dev dependencies.

Running make test-functional fails with config :

test-functional:
@NODE_ENV=test ./node_modules/.bin/mocha
--compilers coffee:coffee-script
--recursive
--reporter $(REPORTER)
--timeout 2000
test/functional

if using global mocha works with config:

test-functional:
@NODE_ENV=test mocha
--compilers coffee:coffee-script
--recursive
--reporter $(REPORTER)
--timeout 2000
test/functional