server: add db heatlh checker to server checkers

move outside dependencies to ./vendor directory

Documentation: update roadmap for 0.4 release cycle

closes #328

server: url decode basic auth credentials

Fixes #336

integration: fix email case sensitivity test

add support for resend an invite email

db: email comparison should be case insensitive

Fix cross compilation

When reading migrations from files, sql-migrate attempts to split
SQL statements. The parsing logic does not handle $BODY$ statements
and broke when the migration included one.

Replace go-bindata with a small migration generation script and use
in memory migrations instead.

Fixes #338

*: remove unused code

This change has no functional changes, it only removes dead code.

This change solves the User's API problem when you want to create an user that its email hasn't been verified yet but it exist.
At now, you can resend invitation email using endpoint /users/{id}/resend-invitation

Fixes #184

db: only allow one open connection for in memory databases

examples: set example app flag defaults to work with --no-db mode

functional: don't fail if postgres or ldap isn't available

user: fix password info JSON encoding to survive round trips

PasswordInfos are marshaled when storing them in the database as
part of the local connector. However, the custom unmarsheler
defined could not unmarshal the standard marshling of this struct.

Add a struct tag to the Password field to correct this.

Closes #332

sqlite3 in memory databases do not support concurrent writes. Limit
number of open connections to prevent race conditions.

move to sqlite3 for --no-db mode and tests

Documentation: update roadmap with issue and PR numbers

Closes #299