Try to fix nix caching

.travis.yml

@@ -9,20 +9,20 @@ git:
 branches:
   only:
   - master
-  - /^\d+\.\d+\.\d+(\.\d+)?$/
-
-cache:
-  directories:
-  - "$HOME/.cabal/store"
-  - "$HOME/.stack"
-  - "$TRAVIS_BUILD_DIR/.stack-work"
+  - /^v\d+\.\d+\.\d+(\.\d+)?$/
 
 matrix:
   include:
   - ghc: 8.6.4
     env: STACK_YAML="$TRAVIS_BUILD_DIR/stack.yaml"
     language: haskell
 
+    cache:
+      directories:
+        - "$HOME/.cabal/store"
+        - "$HOME/.stack"
+        - "$TRAVIS_BUILD_DIR/.stack-work"
+
     install:
       - |
         curl -sSL https://get.haskellstack.org/ | sh
@@ -38,15 +38,15 @@ matrix:
       - |
         echo "Running before_deploy"
 
-        stack build --system-ghc --copy-bins --local-bin-path ./artifacts"
+        stack build --system-ghc --copy-bins --local-bin-path ./artifacts
         cp artifacts/dzen-dhall dzen-dhall
         tar -zcvf "${TRAVIS_OS_NAME}.tar.gz" dzen-dhall
 
     deploy:
       - provider: releases
         api_key: $API_KEY
         file:
-          - ../$TRAVIS_OS_NAME.tar.gz
+          - ./$TRAVIS_OS_NAME.tar.gz
         skip_cleanup: true
         on:
           tags: true
@@ -57,6 +57,7 @@ matrix:
 
     before_install:
     - sudo mkdir -p /etc/nix
+    - sudo touch /etc/nix/nix.conf
     - echo "substituters = https://cache.nixos.org/ file://$HOME/nix.store" | sudo tee -a /etc/nix/nix.conf > /dev/null
     - echo 'require-sigs = false' | sudo tee -a /etc/nix/nix.conf > /dev/null