Added checks to make sure the specified track exists

Added precondition checks to validate input files and paths to return more informative error messages as per #2

node_modules/is-date-object/.travis.yml

@@ -0,0 +1,58 @@
+language: node_js
+node_js:
+  - "4.1"
+  - "4.0"
+  - "iojs-v3.3"
+  - "iojs-v3.2"
+  - "iojs-v3.1"
+  - "iojs-v3.0"
+  - "iojs-v2.5"
+  - "iojs-v2.4"
+  - "iojs-v2.3"
+  - "iojs-v2.2"
+  - "iojs-v2.1"
+  - "iojs-v2.0"
+  - "iojs-v1.8"
+  - "iojs-v1.7"
+  - "iojs-v1.6"
+  - "iojs-v1.5"
+  - "iojs-v1.4"
+  - "iojs-v1.3"
+  - "iojs-v1.2"
+  - "iojs-v1.1"
+  - "iojs-v1.0"
+  - "0.12"
+  - "0.11"
+  - "0.10"
+  - "0.9"
+  - "0.8"
+  - "0.6"
+  - "0.4"
+before_install:
+  - '[ "${TRAVIS_NODE_VERSION}" = "0.6" ] || npm install -g npm@1.4.28 && npm install -g npm'
+sudo: false
+matrix:
+  fast_finish: true
+  allow_failures:
+    - node_js: "4.0"
+    - node_js: "iojs-v3.2"
+    - node_js: "iojs-v3.1"
+    - node_js: "iojs-v3.0"
+    - node_js: "iojs-v2.4"
+    - node_js: "iojs-v2.3"
+    - node_js: "iojs-v2.2"
+    - node_js: "iojs-v2.1"
+    - node_js: "iojs-v2.0"
+    - node_js: "iojs-v1.7"
+    - node_js: "iojs-v1.6"
+    - node_js: "iojs-v1.5"
+    - node_js: "iojs-v1.4"
+    - node_js: "iojs-v1.3"
+    - node_js: "iojs-v1.2"
+    - node_js: "iojs-v1.1"
+    - node_js: "iojs-v1.0"
+    - node_js: "0.11"
+    - node_js: "0.9"
+    - node_js: "0.8"
+    - node_js: "0.6"
+    - node_js: "0.4"