enabled hhvm build in travis
removed basic app tests as they are broken
removed deps from travis.yml
trigger build
WIP merge ActiveRelation into ActiveQuery

allow extending only one class to add scopes, fixes #2146

TODO:

- [ ] adjust guide docs
- [ ] adjust README files of extensions
- [ ] finish work and fix test breaks
made createQuery() config param optional
added missing use statement
merged ActiveQueryInterface and ActiveRelatioInterface
Fixes #2426: Changed URL creation method signatures to be consistent
Allow using string for URL in case there are no parameters
Allow add a condition telling the table to avoid ambiguity error.
Fixes #2508
allow configuring asset converter property with default class
updated docs about active relation
fixed absolute class links in guide
Merge pull request #2497 from yiisoft/merge-query-and-relation2

WIP merge ActiveRelation into ActiveQuery
fixed docs about AR scopes
Corrected redirect in example, used request for getting post instead of global
Fixes #728
Merge pull request #2501 from yiisoft/unify-urls

Fixes #2426: Changed URL creation method signatures to be consistent