Add Bootstrap 4 classes to pagination
Add Bootstrap 4 classes to pagination

I've added the "page-item" and "page-link" classes to the PAGINATION_TEMPLATE. This should cover the class differences for the pagination components of [Bootstrap 3] (http://getbootstrap.com/components/) and [Bootstrap 4] (http://v4-alpha.getbootstrap.com/components/pagination/).
imribarr-compit/ng2-bootstrap,IlyaSurmay/ngx-bootstrap-versioning,olivierceulemans/ng2-bootstrap,vvpanchenko/ng2-bootstrap,JohanSmolders/ng2-bootstrap,vvpanchenko/ng2-bootstrap,valor-software/ngx-bootstrap,lanocturne/ng2-bootstrap,JohanSmolders/ng2-bootstrap,lanocturne/ng2-bootstrap,valor-software/ng2-bootstrap,erodriguezh/ngx-bootstrap,BojanKogoj/ng2-bootstrap,macroorganizm/ng2-bootstrap,BojanKogoj/ng2-bootstrap,Betrozov/ng2-bootstrap,felixkubli/ng2-bootstrap,olivierceulemans/ng2-bootstrap,sublime392/ng2-bootstrap,felixkubli/ng2-bootstrap,JohanSmolders/ng2-bootstrap,macroorganizm/ng2-bootstrap,imribarr-compit/ng2-bootstrap,BojanKogoj/ng2-bootstrap,buchslava/angular2-bootstrap,sublime392/ng2-bootstrap,Betrozov/ng2-bootstrap,buchslava/angular2-bootstrap,Le0Michine/ng2-bootstrap,sublime392/ng2-bootstrap,Betrozov/ng2-bootstrap,lanocturne/ng2-bootstrap,olivierceulemans/ng2-bootstrap,valor-software/ngx-bootstrap,Le0Michine/ng2-bootstrap,valor-software/ngx-bootstrap,felixkubli/ng2-bootstrap,vvpanchenko/ng2-bootstrap,valor-software/ngx-bootstrap,valor-software/ng2-bootstrap,IlyaSurmay/ngx-bootstrap-versioning,buchslava/angular2-bootstrap,macroorganizm/ng2-bootstrap,imribarr-compit/ng2-bootstrap