update github examples to match the working code

I was getting errors like this:

```
bower fluidbox#*               ECMDERR Failed to execute "git ls-remote --tags --heads git@github:hybernaut/Fluidbox", exit code of #128

Additional error details:
ssh: Could not resolve hostname github: nodename nor servname provided, or not known
fatal: Could not read from remote repository.
```
and it turns out the Bowerfile examples should use "git@github.com" instead of "git@github"