0.4.1

Features

• Upgraded to Go 1.8.0
• Upgraded protobuf to 3.2.0
• #233 - Support for link stamping in go_binary and go_test with the linkstamp attribute.
• #272 - Cases within go_test targets can be filtered with --test_filter

Bug fixes

• #257 - gazelle lists loaded symbols in sorted order to avoid conflicts
• #266 - gazelle no longer reformats files with "# gazelle:ignore".
• #274 - cgo libraries are now built with -pthread or -mthreads
• #277 - empty go_prefix("") no longer breaks the linker