travis: don't cache the pinned mysql library
go get -u breaks if not on master.
@@ -18,6 +18,8 @@ matrix:
before_cache:
- rm -rf $GOPATH/src/github.com/GoogleCloudPlatform/golang-samples/*
- rm -rf $GOPATH/pkg/**/github.com/GoogleCloudPlatform/golang-samples
+# go get -u won't work if we've pinned the version.
+- rm -rf $GOPATH/src/github.com/go-sql-driver/mysql
cache:
directories:
