Some specs fail in rails5 branch with errors like
```
1) Group#secret_variables_for when the ref is not protected contains only the secret variables
Failure/Error: variables = Ci::GroupVariable.where(group: list_of_ids)
NoMethodError:
undefined method `arel_table' for Ci::Group:Class
```
This commit fixes it.
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
