CycleDash HTML: Add deployed git hash to navbar

fixes issue #112

![](http://cl.ly/image/3a311T2G132W/Screen%20Shot%202014-10-21%20at%204.56.05%20PM.png)
Suggest wrapping this to avoid making it a fatal error to not run in a git repo:

```python
try:
    DEPLOYED_GIT_HASH = subprocess.check_output(['git', 'rev-parse', 'HEAD'])[:-1]
except subprocess.CalledProcessError:
    DEPOLOYED_GIT_HASH = ''
```