Adding freebsd go build

Author: sarcasticadmin

Makefile

@@ -44,6 +44,8 @@ dist:
 	cp README.md LICENSE plugin.yaml build/diff
 	GOOS=linux GOARCH=amd64 go build -o build/diff/bin/diff -ldflags="$(LDFLAGS)"
 	tar -C build/ -zcvf $(CURDIR)/release/helm-diff-linux.tgz diff/
+	GOOS=freebsd GOARCH=amd64 go build -o build/diff/bin/diff -ldflags="$(LDFLAGS)"
+	tar -C build/ -zcvf $(CURDIR)/release/helm-diff-freebsd.tgz diff/
 	GOOS=darwin GOARCH=amd64 go build -o build/diff/bin/diff -ldflags="$(LDFLAGS)"
 	tar -C build/ -zcvf $(CURDIR)/release/helm-diff-macos.tgz diff/
 	rm build/diff/bin/diff