Enable Dependabot (#85)

* Add Dependabot

* Pin actions to hashes

* Only update github-actions

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
 
     steps:
       - name: Checkout Example.jl
-        uses: actions/checkout@v2
+        uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608
         with:
           repository: julia-actions/Example.jl
 
@@ -41,16 +41,16 @@ jobs:
         shell: bash
 
       - name: Checkout julia-runtest
-        uses: actions/checkout@v2
+        uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608
         with:
           path: ./.github/actions/julia-runtest
 
-      - uses: julia-actions/setup-julia@v1
+      - uses: julia-actions/setup-julia@f40c4b69330df1d22e7590c12e76dc2f9c66e0bc
         with:
           version: ${{ matrix.version }}
           arch: ${{ matrix.arch }}
 
-      - uses: actions/cache@v1
+      - uses: actions/cache@704facf57e6136b1bc63b828d79edcd491f0ee84
         env:
           cache-name: cache-artifacts
         with:
@@ -61,13 +61,13 @@ jobs:
             ${{ runner.os }}-test-
             ${{ runner.os }}-
 
-      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-buildpkg@00f9fd6b2600be0a8d80566dd4d4d2389b3468eb
 
       - uses: ./.github/actions/julia-runtest
 
-      - uses: julia-actions/julia-processcoverage@v1
+      - uses: julia-actions/julia-processcoverage@03114f09f119417c3242a9fb6e0b722676aedf38
 
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@eaaf4bedf32dbdc6b720b63067d99c4d77d6047d
         with:
           file: lcov.info