Check env vars for non-Travis CI platforms

CHANGELOG.md

@@ -26,6 +26,10 @@
 
 * ![Enhancement][badge-enhancement] Videos can now be included in the HTML output using the image syntax (`![]()`) if the file extension matches a known format (`.webm`, `.mp4`, `.ogg`, `.ogm`, `.ogv`, `.avi`). ([#1034][github-1034])
 
+* ![Enhancement][badge-enhancement] `deploydocs` now reads the appropriate environment variables on Travis CI, Gitlab CI, Cirrus CI, Drone CI, and AppVeyor, as does `LaTeXWriter`. However, be aware that CI systems other than Travis CI have not received extensive testing. ([#1067][github-1067])
+
+* ![Enhancement][badge-enhancement] `deploydocs` can now be switched to tag building mode with the `tag` keyword, which overrides the tag information from CI environment variables. ([#1067][github-1067])
+
 * ![Bugfix][badge-bugfix] The HTML output now outputs HTML files for pages that are not referenced in the `pages` keyword too (Documenter finds them according to their extension). But they do exists outside of the standard navigation hierarchy (as defined by `pages`). This fixes a bug where these pages could still be referenced by `@ref` links and `@contents` blocks, but in the HTML output, the links ended up being broken. ([#1031][github-1031], [#1047][github-1047])
 
 * ![Bugfix][badge-bugfix] `makedocs` now throws an error when the format objects (`Documenter.HTML`, `LaTeX`, `Markdown`) get passed positionally. The format types are no longer subtypes of `Documenter.Plugin`. ([#1046][github-1046], [#1061][github-1061])
@@ -375,6 +379,7 @@
 [github-1054]: https://github.com/JuliaDocs/Documenter.jl/pull/1054
 [github-1061]: https://github.com/JuliaDocs/Documenter.jl/pull/1061
 [github-1062]: https://github.com/JuliaDocs/Documenter.jl/pull/1062
+[github-1067]: https://github.com/JuliaDocs/Documenter.jl/pull/1067
 
 [documenterlatex]: https://github.com/JuliaDocs/DocumenterLaTeX.jl
 [documentermarkdown]: https://github.com/JuliaDocs/DocumenterMarkdown.jl

docs/src/lib/internals/documenter.md

@@ -3,4 +3,5 @@
 ```@docs
 Documenter.gitrm_copy
 Documenter.git_push
+Documenter.read_ci_env
 ```

docs/src/lib/public.md

@@ -31,6 +31,17 @@ DocMeta.getdocmeta
 DocMeta.setdocmeta!
 ```
 
+### CI platforms supported by `deploydocs`
+
+```@docs
+Documenter.CI_SYSTEM
+TRAVIS
+GITLAB_CI
+CIRRUS_CI
+DRONE
+APPVEYOR
+```
+
 ## DocumenterTools
 
 ```@docs

docs/src/man/hosting.md

@@ -2,10 +2,17 @@
 
 After going through the [Package Guide](@ref) and [Doctests](@ref) page you will need to
 host the generated documentation somewhere for potential users to read. This guide will
-describe how to setup automatic updates for your package docs using the Travis build service
+describe how to setup automatic updates for your package docs using CI build services
 and GitHub Pages. This is the same approach used by this package to host its own docs --
 the docs you're currently reading.
 
+!!! warning
+
+    Documenter.jl only supports Travis CI, Gitlab CI, Cirrus CI, Drone CI, and AppVeyor.
+
+    If you want to use another CI service, please either [open an issue](https://github.com/JuliaDocs/Documenter.jl/issues/new)
+    or set the relevant environment variables yourself.
+
 !!! note
 
     Following this guide should be the *final* step you take after you are comfortable with
@@ -14,8 +21,8 @@ the docs you're currently reading.
     documentation locally with Documenter.
 
     This guide assumes that you already have [GitHub](https://github.com/) and
-    [Travis](https://travis-ci.com/) accounts setup. If not then go set those up first and
-    then return here.
+    a CI system, like [Travis](https://travis-ci.com/) accounts setup. If not,
+    then go set those up first and then return here.
 
 
 ## Overview

docs/src/man/hosting/walkthrough.md

@@ -130,7 +130,8 @@ to GitHub. The next step is to add the private key to Travis.
 
 In this section, we explain how to upload a private SSH key to Travis. By this point, you
 should have generated a private key and saved it to a file. If you haven't done this, go
-read [Generating an SSH Key](@ref).
+read [Generating an SSH Key](@ref).  If you are using a different CI system, you will need
+to do something else - consult your CI system's documentation.
 
 First, we need to Base64 encode the private key. Open Julia, and run the command