Grant create view permission to db user
Merge pull request #528 from Verdacom/grant_create_view_to_db_user

Grant create view privilege to db user
Read SYSTEM password from ENV ORACLE_SYSTEM_PASSWORD optionally

This is useful when running scripts and no user is around to enter
a system password value. In particular, for various CI server setups.

Usage Example:

```
ORACLE_SYSTEM_PASSWORD=secret rake db:migrate
```
Require 'active_record/base' in rake task

This may cause `Rails.application.config.active_record` inside of
an initializer no effects.
Merge pull request #530 from yahonda/backport_526_to_master

Require 'active_record/base' in rake task
Merge pull request #529 from Verdacom/allow-optional-env-variable-for-system-password

Read SYSTEM password from ENV ORACLE_SYSTEM_PASSWORD optionally
Document ORACLE_SYSTEM_PASSWORD env variable alternative in db:create
Merge pull request #531 from Verdacom/document-environment-variable-usage-in-rake-task

Document ORACLE_SYSTEM_PASSWORD env variable alternative in db:create
Show original error message when loading ruby-oci8 library fails

While I had the ruby-oci8 library already installed, I was puzzled
by this error:

> ERROR: ActiveRecord oracle_enhanced adapter could not load
ruby-oci8 library. Please install ruby-oci8 gem.

After revealing the original load error received, I discovered that
the original message was:

> LoadError: libaio.so.1: cannot open shared object file: No such
file or directory

So I got rid of this (on Travis CI), by installing `libaio1` via
`sudo apt-get install libaio1`