v2.0.1: Fix vendor search path for v2

Fix for gopkg.in installs.

v2.0.0

The biggest change since v1.x is that linting is now much more efficient thanks to changes by Daniel Nephin (@dnephin). Instead of invoking each linter for every directory, linters are invoked the minimum number of times necessary by passing as many directories, packages or files as they will accept in a single invocation.

The configuration format has also changed, but should be mostly backwards compatible.

Another major change is that from now on we will be releasing binary packages. gometalinter's management of linter installation will soon be deprecated, and eventually removed.