adds bill and associated models

customers, suppliers, categories added with minimum validation
Squashed commit of the following:

commit 31d0140dfbaaf3ce0c0be61e9f483096808d35dc
Author: Owen Bannister <owen@bandadbro.com>
Date:   Thu Jan 30 09:31:38 2014 +0000

    adds date to bills and datepicker

commit 83a2a30048b67f2b121ca04d4869cca7716c920d
Author: Owen Bannister <owen@bandadbro.com>
Date:   Thu Jan 30 08:47:39 2014 +0000

    adds validation tests

commit 517293eeb0fe02fadd763d04de1746fa36027f78
Author: Owen Bannister <owen@bandadbro.com>
Date:   Wed Jan 29 15:27:56 2014 +0000

    updates bill feature steps to use form entry

commit 063f9e621ed44881c2ad26c2cb4b254b01c843bc
Author: Owen Bannister <owen@bandadbro.com>
Date:   Tue Jan 28 21:41:52 2014 +0000

    add bill form and new views plus step definitions for bills feature

commit 18413af36fc4f7c7ad9507ab8f48134eaa4b388e
Author: Owen Bannister <owen@bandadbro.com>
Date:   Tue Jan 28 18:23:30 2014 +0000

    add BillsController

commit a79b850e94bdb61fc921c9741c6a4334ba3da65d
Author: Owen Bannister <owen@bandadbro.com>
Date:   Tue Jan 28 18:14:13 2014 +0000

    adds models for customer, supplier, category and bill

commit 6d2060e405318d4f9c8caa2b0361cc8553c1b5fc
Author: Owen Bannister <owen@bandadbro.com>
Date:   Tue Jan 28 17:31:50 2014 +0000

    start test setup for bills
Adds customer processing including index, new, edit and delete

Squashed commit of the following:

commit 2fc1644d6abc7a576b6c738878e6956d91ba6959
Author: Owen Bannister <owen@bandadbro.com>
Date:   Fri Jan 31 16:15:24 2014 +0000

    improve customer model spec

commit 75a4a5ddc756e412558df9185647d2adb1262131
Author: Owen Bannister <owen@bandadbro.com>
Date:   Fri Jan 31 15:00:53 2014 +0000

    add destroy action to customer

commit 2915db1dfb5f6b48a6eccdee34ad5636ac7a3faa
Author: Owen Bannister <owen@bandadbro.com>
Date:   Fri Jan 31 14:30:17 2014 +0000

    add Rspec macros and start on controller specs

commit fb9782cb6f983a860a2e250ef79b624255510c20
Author: Owen Bannister <owen@bandadbro.com>
Date:   Thu Jan 30 17:54:03 2014 +0000

    add row_select javascript and tidy views

commit 75f8cdd332c2b6cf0f88e10e09c57ca410c3ede3
Author: Owen Bannister <owen@bandadbro.com>
Date:   Thu Jan 30 11:07:53 2014 +0000

    add customer new and form views

commit 4cfced74aff2fbcc8829b5bf8ab108e757f068b5
Author: Owen Bannister <owen@bandadbro.com>
Date:   Thu Jan 30 10:47:35 2014 +0000

    add customer controller

commit b3566ef4b91052459431c2aeda90ed6ca3ab1898
Author: Owen Bannister <owen@bandadbro.com>
Date:   Thu Jan 30 10:24:44 2014 +0000

    add customer feature