Adds tests

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/2878

Fixed MR single button submit failure and attempted to tidy up close_reopen partials using issuable_helpers and setDisable will use true as default bool

Dont show toggle if only one action is available and do not show report as abuse for current_user's issuables

Fix static-snalysis

Move the precedence of group secure variable before project secure variable. Allow project_id to be null.

Separate Ci::VariableProject and Ci::VariableGroup

Add the forgotton files

Add migration file to update type of ci_variables

Fix form_for fpr VariableProject

Fix test

Change the table structure according to the yorik advice

Add necessary migration files. Remove unnecessary migration spec.

Revert safe_model_attributes.yml

Fix models

Fix spec

Avoid self.variable. Use becomes for correct routing.

Use unique index on group_id and key

Add null: false for t.timestamps

Fix schema version

Rename VariableProject and VariableGroup to ProjectVariable and GroupVariable

Rename the rest of them

Add the rest of files

Basic BE change

Fix static-snalysis

Move the precedence of group secure variable before project secure variable. Allow project_id to be null.

Separate Ci::VariableProject and Ci::VariableGroup

Add the forgotton files

Add migration file to update type of ci_variables

Fix form_for fpr VariableProject

Fix test

Change the table structure according to the yorik advice

Add necessary migration files. Remove unnecessary migration spec.

Revert safe_model_attributes.yml

Fix models

Fix spec

Avoid self.variable. Use becomes for correct routing.

Use unique index on group_id and key

Add null: false for t.timestamps

Fix schema version

Rename VariableProject and VariableGroup to ProjectVariable and GroupVariable

Rename the rest of them

Add the rest of files

Implement CURD

Rename codes related to VariableGroup and VariableProject FE part

Remove unneccesary changes

Make Fe code up-to-date

Add protected flag to migration file

Protected group variables essential package

Update schema

Improve doc

Fix logic and spec for models

Fix logic and spec for controllers

 Fix logic and spec for views(pre feature)

Add feature spec

Fixed bugs. placeholder. reveal button. doc.

Add changelog

Remove unnecessary comment

godfat nice catches

Improve secret_variables_for arctecture

Fix spec

Fix StaticAnlysys & path_regex spec

Revert "Improve secret_variables_for arctecture"

This reverts commit c3216ca212322ecf6ca534cb12ce75811a4e77f1.

Use ayufan suggestion for secret_variables_for

Use find instead of find_by

Fix spec message for variable is invalid

Fix spec remove variable.group_id = group.id

godffat spec nitpicks

Use include Gitlab::Routing.url_helpers for presenter spec

See https://gitlab.slack.com/archives/C5XGWBRJA/p1499355359953774