diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 59a9ffc..ec9c30f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,7 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.6'
+          - 'lts'
           - '1' # automatically expands to the latest stable 1.x release of Julia.
         os:
           - ubuntu-latest
@@ -25,11 +25,11 @@ jobs:
           - x64
     steps:
       - uses: actions/checkout@v2
-      - uses: julia-actions/setup-julia@v1
+      - uses: julia-actions/setup-julia@v2
         with:
           version: ${{ matrix.version }}
           arch: ${{ matrix.arch }}
-      - uses: actions/cache@v1
+      - uses: julia-actions/cache@v2
         env:
           cache-name: cache-artifacts
         with:
diff --git a/.github/workflows/ci_nightly.yml b/.github/workflows/ci_nightly.yml
deleted file mode 100644
index dbb29cd..0000000
--- a/.github/workflows/ci_nightly.yml
+++ /dev/null
@@ -1,50 +0,0 @@
-name: CI (Julia nightly)
-on:
-  pull_request:
-    branches:
-      - master
-      - dev
-  push:
-    branches:
-      - master
-      - dev
-    tags: '*'
-env:
-  TEST_MLJBASE: "true"
-jobs:
-  test:
-    name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }} - ${{ github.event_name }}
-    runs-on: ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        version:
-          - 'nightly'
-        os:
-          - ubuntu-latest
-        arch:
-          - x64
-    steps:
-      - uses: actions/checkout@v2
-      - uses: julia-actions/setup-julia@v1
-        with:
-          version: ${{ matrix.version }}
-          arch: ${{ matrix.arch }}
-      - uses: actions/cache@v1
-        env:
-          cache-name: cache-artifacts
-        with:
-          path: ~/.julia/artifacts
-          key: ${{ runner.os }}-test-${{ env.cache-name }}-${{ hashFiles('**/Project.toml') }}
-          restore-keys: |
-            ${{ runner.os }}-test-${{ env.cache-name }}-
-            ${{ runner.os }}-test-
-            ${{ runner.os }}-
-      - uses: julia-actions/julia-buildpkg@v1
-      - uses: julia-actions/julia-runtest@v1
-        env:
-          JULIA_NUM_THREADS: 2
-      - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v1
-        with:
-          file: lcov.info