Improve the email store plugin:

* Allow overwrite of data
* Clean up code
* Improve tests
Merge pull request #212 from eordano/feature/betterEmailPlugin

Improvements to email storage plugin
Add email plugin configuration to the README
Merge pull request #214 from eordano/feature/betterEmailPlugin

Add email plugin configuration to the README
Add key/value storage differentiated by email
Merge pull request #215 from eordano/feature/betterEmailPlugin

Add key/value storage differentiated by email
Fixes testing error
Merge pull request #216 from eordano/feature/betterEmailPlugin

Fixes testing error
Add email templates for copay
Merge pull request #217 from eordano/feature/emailTemplates

Add email templates for copay
Fixes express configuration
Merge pull request #219 from bitpay/fix/emailstoreConfig

Fixes express configuration
Fixes email template and redirection to copay
Merge pull request #220 from eordano/fix/emailtemplate

Fixes email template and add redirection to copay
only add routes for email store if plugin enabled
fixes url for email confirmation
Merge pull request #222 from eordano/fix/confirmUrl

Fixes url for email confirmation
Merge pull request #221 from eordano/fix/enablePlugin

only add routes for email store if plugin enabled
fix log message
chagne email