Correctly detect browser vs node environment

[victorb]

Change conditional to not try to access the window object (which throws error when window doesn't exist), instead we check the typeof so it doesn't crash if window is not defined.

We can also safely assume that window.location exists if window exists.

This closes issue #62

[victorb]

Ok, I've run the tests locally, all of them are passing. In CircleCI, ls is stepping over the timeout, so the tests are failing. In Travis, we get some cryptic message TypeError: Cannot read property 'pkg' of null which I have no idea why that happens. @diasdavid care to take a look?

[victorb]

Ok, was able to reproduce the travis problem after updating dependencies.

It seems that commit 5c12f11d784498add132b3ebedefcd0dbc23ae2b in ipfs/node-ipfsd-ctl broke the module for both Mac and what Travis CI is using. What's weird is that master for this project is passing but only on Travis. Locally the build is broken, wondering if it's some Travis cache. What I can see, ipfs/node-ipfsd-ctl is also passing on master locally for me, but not in this project.

[victorb]

Submitted PR #64 to fix the tests which will make this PR green as well.

[RichardLitt]

👍 Good catch.