Merge pull request #58 from apigee/development

Development
add bower json
Merge pull request #61 from apigee/bower-json

add bower json
Adding a check to see if a username already exists.
Merge pull request #62 from stevetraut/master

Adding a check to see if a username already exists.
Merge branches 'development' and 'master' of github.com:apigee/apigee-javascript-sdk
Adding Contribution.md
pushing apigee.js v2.0.6, adding asset sample
re-syncing the public javascript sdk.

Merge branch 'development' of github.com:apigee/apigee-javascript-sdk into development