Search for all available cloudlets

Enable `nepho cloudlet search` to return all available cloudlets when
called with no arguments.
Merge pull request #128 from huit/bugfix/search-without-arg

Search for all available cloudlets
Change cloudlet registry refresh interval to 4 hours
Adding cwd convenience method for future use
Code cleanup, fixed almost all style errors
Removing old aws directory

Relevant pieces have been merged into aws provider or will be moved to
stdlib.
Ignore vagrant syntax errors -- presumably these things are being done
for a reason
Merge branch 'master' of github.com:huit/nepho
Fixing what I broke
steve's change broke the build
implement CLI code to refer to scope configs as well as command line.
remove print statement for debugging
lets a user set vagrant_provider config to control the provider used by vagrant to deploy VMs.
cleanup whitespace to make travis happy.
cleanup whitespace to make travis happy take 2.
cleanup whitespace to make travis happy take 3.
cleanup whitespace to make travis happy take 4.
cleanup whitespace to make travis happy take 5.
Merge pull request #130 from huit/feature/set-vagrant-provider

lets a user set vagrant_provider config to control the provider used by ...
Merge pull request #131 from huit/feature/integrate-scope

Feature/integrate scope