Sporadic false positives due to stream-equal 0.1.7

[IgorMinar]

When upgrading transitive dependencies of gulp-clang-format in angular/angular I started seeing frequent but random false positives when running gulp check-format.

I was able to narrow the issue down to gulp-clang-format's stream-equal dependency. Version 0.1.6 works just fine but 0.1.7 exhibits this problem.

I haven't investigated if this is happening due to a bug in stream-equal or due to how we use it.

For now I'm going to limit the stream-equal transitive dependency of gulp-clang-format to <=0.1.6.