dillon1000/react

Fix travis artifact upload

Changes:
 - moves after_script to script
 - adds `set -e`
 - creates a seperate matrix 'build'

Way at the bottom of the travis output:

```
1571: curl: (26) couldn't open file "build/react.tgz"
```

This seems to be broken since 12c9fee94ed97dee1ae0dad701c03d4fc14ca0a7