Merge branch 'issue-boards-ui' into 'issue-boards'

Issue boards UI

## What does this MR do?

UI for issue boards.

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

## What are the relevant issue numbers?

-  Issue: #17907
-  Backend MR: !5548
-  Frontend MR: !5554
- Documentation !5713 

## Screenshots (if relevant)

![Screen_Shot_2016-08-17_at_14.06.06](/uploads/e2abed987d2c2d280e8b8034c8949024/Screen_Shot_2016-08-17_at_14.06.06.png)


See merge request !5554
42 jobs from issue-boards in 616 minutes and 37 seconds (queued for 10 seconds)
Status Job ID Name Coverage
  Prepare
passed #3171965
knapsack

00:01:06

 
  Test
passed #3172005
license_finder

00:04:21

passed #3172009
lint-doc

00:02:49

passed #3172002
rake brakeman

00:04:03

passed #3172007
rake db:migrate:reset

00:04:02

passed #3172006
rake downtime_check

00:02:56

passed #3172004
rake flay

00:03:07

passed #3172003
rake flog

00:02:50

passed #3172001
rake scss_lint

00:03:32

passed #3171966
rspec 0 20

00:24:44

passed #3171967
rspec 1 20

00:20:54

passed #3171976
rspec 10 20

00:25:43

passed #3171977
rspec 11 20

00:18:59

passed #3171978
rspec 12 20

00:24:03

passed #3171979
rspec 13 20

00:29:32

passed #3171980
rspec 14 20

00:18:58

passed #3171981
rspec 15 20

00:16:53

passed #3171982
rspec 16 20

00:19:31

passed #3171983
rspec 17 20

00:25:06

passed #3171984
rspec 18 20

00:16:52

passed #3171985
rspec 19 20

00:17:24

passed #3171968
rspec 2 20

00:19:40

passed #3171969
rspec 3 20

00:28:16

passed #3171970
rspec 4 20

00:18:50

passed #3171971
rspec 5 20

00:20:38

passed #3171972
rspec 6 20

00:21:54

passed #3171973
rspec 7 20

00:26:09

passed #3171974
rspec 8 20

00:19:01

passed #3171975
rspec 9 20

00:24:12

passed #3172000
rubocop

00:05:14

passed #3171986
spinach 0 10

00:20:27

passed #3171987
spinach 1 10

00:11:22

passed #3171988
spinach 2 10

00:16:55

passed #3171989
spinach 3 10

00:10:14

passed #3171990
spinach 4 10

00:11:40

passed #3171991
spinach 5 10

00:10:38

passed #3171992
spinach 6 10

00:10:15

passed #3171993
spinach 7 10

00:11:50

passed #3171994
spinach 8 10

00:20:12

passed #3171999
spinach 9 10

00:09:59

passed #3172008
teaspoon

00:07:46

 
  Post Test
passed #3172010
coverage

00:03:39

89.77%