compat upper bounds, compat helper github action

github actions to run:
- every monday at 1:30 UTC for compat helper
- every tuesday at 10am UTC for tagbot

.github/workflows/CompatHelper.yml

@@ -0,0 +1,16 @@
+name: CompatHelper
+
+on:
+  schedule:
+    - cron: '30 01 * * MON'
+
+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: '00 10 * * TUE'
 jobs:
   TagBot:
     runs-on: ubuntu-latest

Project.toml

@@ -14,11 +14,13 @@ Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 RCall = "6f49c342-dc21-5d91-9882-a32aef131414"
 
 [compat]
-DataFrames = "≥ 0.13.0"
-Gadfly = "≥ 1.0.0"
-PhyloNetworks = "≥ 0.9.0"
-RCall = "≥ 0.11.0"
-julia = "≥ 0.7.0"
+ColorTypes = "0.7, 0.8, 0.9, 0.10"
+Colors = "0.9, 0.10, 0.11, 0.12"
+DataFrames = "0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20"
+Gadfly = "1.0, 1.1, 1.2"
+PhyloNetworks = "0.9, 0.10, 0.11"
+RCall = "0.11, 0.12, 0.13"
+julia = "0.7, 1.0, 1.1, 1.2, 1.3, 1.4"
 
 [extras]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"