Add non-cgo builds for Linux.

.travis/script

@@ -60,15 +60,15 @@ export BUILDNAME="by travis"
 BUILDINFO="$($GOPATH/src/github.com/hlandau/degoutils/buildinfo/gen $BINARIES)"
 
 # cgo crosscompile
-gox -ldflags "$BUILDINFO" -cgo -osarch 'linux/amd64' -output "$GOPATH/releasing/idist/acmetool-$TRAVIS_TAG-{{.OS}}_{{.Arch}}/bin/{{.Dir}}" $BINARIES
+gox -ldflags "$BUILDINFO" -cgo -osarch 'linux/amd64' -output "$GOPATH/releasing/idist/acmetool-$TRAVIS_TAG-{{.OS}}_{{.Arch}}_cgo/bin/{{.Dir}}" $BINARIES
 RESULT1=$?
-GO386=387 gox -ldflags "$BUILDINFO" -cgo -osarch 'linux/386' -output "$GOPATH/releasing/idist/acmetool-$TRAVIS_TAG-{{.OS}}_{{.Arch}}/bin/{{.Dir}}" $BINARIES
+GO386=387 gox -ldflags "$BUILDINFO" -cgo -osarch 'linux/386' -output "$GOPATH/releasing/idist/acmetool-$TRAVIS_TAG-{{.OS}}_{{.Arch}}_cgo/bin/{{.Dir}}" $BINARIES
 RESULT2=$?
 
 # non-cgo crosscompile
-gox -ldflags "$BUILDINFO" -osarch 'darwin/amd64 linux/arm linux/arm64 freebsd/amd64 freebsd/arm openbsd/amd64 netbsd/amd64 netbsd/arm dragonfly/amd64 solaris/amd64' -output "$GOPATH/releasing/idist/acmetool-$TRAVIS_TAG-{{.OS}}_{{.Arch}}/bin/{{.Dir}}" $BINARIES
+gox -ldflags "$BUILDINFO" -osarch 'darwin/amd64 linux/amd64 linux/arm linux/arm64 freebsd/amd64 freebsd/arm openbsd/amd64 netbsd/amd64 netbsd/arm dragonfly/amd64 solaris/amd64' -output "$GOPATH/releasing/idist/acmetool-$TRAVIS_TAG-{{.OS}}_{{.Arch}}/bin/{{.Dir}}" $BINARIES
 RESULT3=$?
-GO386=387 gox -ldflags "$BUILDINFO" -osarch 'darwin/386 freebsd/386 openbsd/386 netbsd/386' -output "$GOPATH/releasing/idist/acmetool-$TRAVIS_TAG-{{.OS}}_{{.Arch}}/bin/{{.Dir}}" $BINARIES
+GO386=387 gox -ldflags "$BUILDINFO" -osarch 'linux/386 darwin/386 freebsd/386 openbsd/386 netbsd/386' -output "$GOPATH/releasing/idist/acmetool-$TRAVIS_TAG-{{.OS}}_{{.Arch}}/bin/{{.Dir}}" $BINARIES
 RESULT4=$?
 
 # Defer exiting to get as much error output as possible upfront.