Drafter version does not work for CMake builds

[kylef]

When building with CMake, the version is returned as "Non-oficial drafter gyp-based build", which is incorrect.

$ ./src/drafter --version
Non-oficial drafter gyp-based build

It would look like the code here is incorrect, and designed so that it checks for the presence of a macro CMAKE_BUILD_TYPE, which I don't think is ever set and thus always returns GYP version.

drafter/src/drafter.cc

Line 234 in 32f5f87

#if defined CMAKE_BUILD_TYPE