Canary replace literal strings with constant strings

Beginning to replace literal strings with constant strings. I have added a basic unit test which can be run using Jasmine, and I have added code coverage using Istanbul so we can see what code is not yet covered by tests. 

I updated setup.sh to install jasmine and istanbul if they are not already present (must be run as root, because it modifies /usr/bin. Directs the user how to do it manually if setup.sh is not run as root). Once they are installed you can type 
```
jasmine
```

to run all unit tests, and 
```
istanbul cover jasmine
```

to generate code coverage reports in the directory ./coverage

Also, refactored ./bin/lamassu-machine to extract the configuration code. This was necessary so that unit tests could create Brain without going through lamassu-machine.