Revert "Remove conan cache, as it mostly causes issues."

This reverts commit 4a1efd28

.drone.yml

@@ -1,10 +1,19 @@
 kind: pipeline
 name: default
 
+
+volumes:
+  - name: conan-data
+    host:
+      path: /root/.conan/data
+
 type: docker
 steps:
   - name: test-debug-linux
     image: deukhoofd/linux64builder
+    volumes:
+      - name: conan-data
+        path: /root/.conan/data
     environment:
       CC: clang
       CXX: clang++
@@ -15,6 +24,9 @@ steps:
       - build-debug/bin/pkmnLibTests -s --durations yes --use-colour yes
   - name: test-release-linux
     image: deukhoofd/linux64builder
+    volumes:
+      - name: conan-data
+        path: /root/.conan/data
     environment:
       CC: clang
       CXX: clang++
@@ -25,6 +37,9 @@ steps:
       - build-release/bin/pkmnLibTests -s --durations yes --use-colour yes
   - name: valgrind-release-linux
     image: deukhoofd/linux64builder
+    volumes:
+      - name: conan-data
+        path: /root/.conan/data
     commands:
       - valgrind --tool=memcheck --gen-suppressions=all --leak-check=full --leak-resolution=med --track-origins=yes --vgdb=no --error-exitcode=1 --suppressions=angelscript.supp build-release/bin/pkmnLibTests
   - name: test-release-windows
@@ -56,6 +71,9 @@ steps:
       - wine build-release-windows/bin/pkmnLibTests.exe -s
   - name: conan-deploy
     image: deukhoofd/linux64builder
+    volumes:
+      - name: conan-data
+        path: /root/.conan/data
     environment:
       CONAN_LOGIN_USERNAME:
         from_secret: conan_username