fix: update save_cache step to use tmp python-version file (#105)

Author: Jaryt

.gitignore

@@ -4,4 +4,5 @@ orb.yml
 sample_pip/*/__pycache__
 
 # dev tools
-.idea
+.idea
+**/.DS_Store

src/commands/install-packages.yml

@@ -182,6 +182,6 @@ steps:
               PARAM_VENV_PATH: << parameters.venv-path >>
             command: <<include(scripts/cache-save.sh)>>
         - save_cache:
-            key: <<parameters.cache-version>>-cci_pycache-<<#parameters.include-branch-in-cache-key>>{{ .Branch }}-<</parameters.include-branch-in-cache-key>>{{ checksum "/tmp/cci_pycache/lockfile" }}-<<#parameters.include-python-in-cache-key>>{{ checksum "/home/circleci/.pyenv/version" }}-<</parameters.include-python-in-cache-key>>
+            key: <<parameters.cache-version>>-cci_pycache-<<#parameters.include-branch-in-cache-key>>{{ .Branch }}-<</parameters.include-branch-in-cache-key>>{{ checksum "/tmp/cci_pycache/lockfile" }}-<<#parameters.include-python-in-cache-key>>{{ checksum "/tmp/python-version" }}-<</parameters.include-python-in-cache-key>>
             paths:
               - /tmp/cci_pycache