Some CI improvements

* Add CompatHelper
* Reduce frequency of TagBot to once per day
* Remove Cirrus script, it's not working properly lately
* Add FreeBSD to Travis
* Run Travis only on master and a few special-named branches
* Cache artifacts in Travis and AppVeyor

.github/workflows/CompatHelper.yml

@@ -0,0 +1,16 @@
+name: CompatHelper
+
+on:
+  schedule:
+    - cron: '18 06 * * *'
+
+jobs:
+  CompatHelper:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Pkg.add("CompatHelper")
+        run: julia -e 'using Pkg; Pkg.add("CompatHelper")'
+      - name: CompatHelper.main()
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: julia -e 'using CompatHelper; CompatHelper.main()'

.github/workflows/TagBot.yml

@@ -1,7 +1,7 @@
 name: TagBot
 on:
   schedule:
-    - cron: 0 * * * *
+    - cron: 37 09 * * *
 jobs:
   TagBot:
     runs-on: ubuntu-latest

.travis.yml

@@ -2,16 +2,16 @@
 language: julia
 os:
   - linux
+  - freebsd
   - osx
   - windows
 julia:
   - 1.3
   - nightly
 env:
-  matrix:
-    - JULIA_FFTW_PROVIDER=FFTW
-    - JULIA_FFTW_PROVIDER=MKL
-    - JULIA_NUM_THREADS=2
+  - JULIA_FFTW_PROVIDER=FFTW
+  - JULIA_FFTW_PROVIDER=MKL
+  - JULIA_NUM_THREADS=2
 notifications:
   email: false
 # uncomment the following lines to override the default test script
@@ -21,7 +21,22 @@ notifications:
 after_success:
   - julia -e 'using Pkg; Pkg.add("Coverage"); Pkg.dir("FFTW"); using Coverage; Coveralls.submit(Coveralls.process_folder())'
 
+branches:
+  only:
+  - master
+  - gh-pages # For building documentation
+  - /^testing-.*$/ # testing branches
+  - /^v[0-9]+\.[0-9]+\.[0-9]+$/ # version tags
+
+cache:
+  directories:
+    - $HOME/.julia/artifacts
+
 jobs:
+  exclude:
+    - os: freebsd
+      env:
+        - JULIA_FFTW_PROVIDER=MKL
   include:
     - stage: "Documentation"
       julia: 1.3

appveyor.yml

@@ -3,6 +3,9 @@ environment:
   - julia_version: 1.3
   - julia_version: nightly
 
+cache:
+  - '%USERPROFILE%\.julia\artifacts'
+
 platform:
   - x86 # 32-bit
   - x64 # 64-bit