Merge pull request #24 from Clever/INFRA-2318-go-versions

golang-install: add 1.8, update 1.7

Author: nathanleiby

circleci/golang-install

@@ -22,7 +22,8 @@ echo "Attempting to download Go version '$GO_VERSION'..."
 if [ "$GO_VERSION" == "1.4" ]; then GO_VERSION="1.4.3"; fi
 if [ "$GO_VERSION" == "1.5" ]; then GO_VERSION="1.5.4"; fi
 if [ "$GO_VERSION" == "1.6" ]; then GO_VERSION="1.6.4"; fi
-if [ "$GO_VERSION" == "1.7" ]; then GO_VERSION="1.7.4"; fi
+if [ "$GO_VERSION" == "1.7" ]; then GO_VERSION="1.7.5"; fi
+if [ "$GO_VERSION" == "1.8" ]; then GO_VERSION="1.8.1"; fi
 
 GODIST=go$GO_VERSION.linux-amd64.tar.gz