chore(sdk): Fixing failures with Typescript 2.4 + Travis (#1076)

* Fixing the type failure in Typescript 2.4, ListObversable is now any, rather than any[]
* Use node stable on Travis
* Type fixes in the specs
* Ditching yarn due to the typescript problems on Travis
* Closes #1072

Author: jamesdaniels

.travis.yml

@@ -1,7 +1,7 @@
 language: node_js
 sudo: false
 node_js:
-- '6'
+- 'node'
 
 addons:
   firefox: latest
@@ -11,16 +11,14 @@ addons:
     packages:
       - g++-4.8
 
-cache:
-  directories:
-    - node_modules
+cache: npm
 
 env:
   - CXX=g++-4.8
 
 install:
-  - npm install -g yarn
-  - yarn install
+  # ditched yarn, since it was acting up and giving old versions of tsc
+  - npm install
 
 before_script:
   - export DISPLAY=:99.0