GitLab

* updated travis

* renamed OSX->macOS; updated gcc installation on macOS

* updated travis macos installation

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* updated installation guide for macos

* fixed spelling

* renamed appveyor file

* updated Travis

* Update GPU-Tutorial.rst

* Update Installation-Guide.rst

* Update GPU-Tutorial.rst

* fixed typos and hotfixes

* converted gcc-tips.Rmd; added ref to gcc-tips

* renamed files

* renamed Advanced-Topics

* renamed README

* renamed Parameters-Tuning

* renamed FAQ

* fixed refs to FAQ

* fixed undecodable source characters

* renamed Features

* renamed Quick-Start

* fixed undecodable source characters in Features

* renamed Python-Intro

* renamed GPU-Tutorial

* renamed GPU-Windows

* fixed markdown

* fixed undecodable source characters in GPU-Windows

* renamed Parameters

* fixed markdown

* removed recommonmark dependence

* hotfixes

* added anchors to links

* fixed 404

* fixed typos

* added more anchors

* removed sphinxcontrib-napoleon dependence

* removed outdated line in Travis config

* fixed max-width of the ReadTheDocs theme

* added horizontal align to images