Add Affiliation model

[Refs #72499862]
Add user - affiliation relationship

Added many-to-many relationship for users/affiliations.
Join table created.
Add select for affiliations on the welcome page

[Refs #72499862]
Add professional info to User model

[Refs #72499862]
Added fields:
* company_name
* homepage
* professional_affiliation
* about_me
* education
Add bootstrap

[#72499862]

Required bootstrap in application.css
Add professional info fields to the sign up form

[Refs #72499862]
Add Profession model

[Refs #72499862]

Generated Profession model, migrated the database.
Add user-profession relationship

[Refs #72499862]
Added many-to-many user/profession relationship.
Created join table, migrated db.
Update welcome.html.slim

[Refs #72499862]

Changed the layout a bit, added input for professions.
Update users_controller

[Refs #72499862]

Made profession ids a permitted field.
Add ProfilePicture to User

[Refs #72499862]
Generated ProfilePicture uploader, generated required migrations,
migrated the db.
Update .gitignore

[Refs #72499862]

Added /public/uploads folder to .gitignore
Update UsersController, 'welcome' layout

[Refs #72499862]

Added file_field to the layout, made profile_picture a permitted param.
Add Country model

[Refs #72499862]

Generated Country model, established association between Users and
Countries, added country select on the ‘welcome’ page.
Add Link model

Created new model, that keeps user’s links to social sites
Update UsersController

[Refs #72499862]

Updated UsersController to accept links,
updated User model (has_one :link)
Update Gemfile

Updated rspec to 3.0.1
Generate rspec helpers

[Refs #72499862]
Update user.rb
Merge branch 'development' into ft/user-sign-up-72499862

Conflicts:
	.rspec
	spec/rails_helper.rb