Formatting and fix of string formatting issue

Should fix the following error:
```
File "/usr/local/lib/python2.7/dist-packages/ebs_deploy/__init__.py", line 467, in wait_for_environments
    raise Exception("Wait time for environment(s) "+(" and ".join(environment_names))+" to be "+health+" expired")
TypeError: cannot concatenate 'str' and 'NoneType' objects
```
Log events from ebs to file, formatting
Flag doesn't require value
Fix typo in wait_for_environments
Merge pull request #16 from Syncano/deploy_improvements

Deploy improvements