Split the Travis build into multiple partitions
Split the Travis build into multiple partitions

- Cloud APIs beginning with A-L
- Cloud APIs beginning with M-Z
- Non-Cloud APIs

This can be tweaked over time as we wish

iantalarico/google-cloud-dotnet,googleapis/google-cloud-dotnet,jskeet/google-cloud-dotnet,jskeet/google-cloud-dotnet,jskeet/google-cloud-dotnet,evildour/google-cloud-dotnet,evildour/google-cloud-dotnet,iantalarico/google-cloud-dotnet,jskeet/gcloud-dotnet,googleapis/google-cloud-dotnet,jskeet/google-cloud-dotnet,iantalarico/google-cloud-dotnet,evildour/google-cloud-dotnet,jskeet/google-cloud-dotnet,googleapis/google-cloud-dotnet