when I run go get I get this error: go get github.com/sourcegraph/go-webkit2/webkit2
pkg-config --cflags javascriptcoregtk-3.0
Package javascriptcoregtk-3.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `javascriptcoregtk-3.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'javascriptcoregtk-3.0' found
pkg-config: exit status 1