release: Move eris to ubuntu 21.10.

- Update readme.
- php7 -> php8.
- Fix python-coverage.
- Also need python decorator module.
- Replaced Mcrt1 with rotatingtree since Mcrt1 started raising
  a new warning.

eris/tools.py

@@ -324,7 +324,7 @@ def python_coverage(path):
              "annotate", "--directory", temp_dir, path])
         if returncode != 0:
             return Status.problem, stdout
-        cover_filename = path.replace("/", "_") + ",cover"
+        cover_filename = os.listdir(temp_dir)[0]
         with open(os.path.join(temp_dir, cover_filename), "r") as f:
             lines = f.read().splitlines(keepends=True)
     failed_lines = [line for line in lines if line.startswith("! ")]

eris/tools.toml

@@ -14,7 +14,7 @@ tools_for_extensions = [
    [["rb"], ["ruby_syntax"]],
    [["lua"], ["lua_syntax", "lua_check"]],
    [["js"], ["js_syntax"]],
-   [["php"], ["php7_syntax"]],
+   [["php"], ["php8_syntax"]],
    [["go"], ["go_vet", "godoc"]],
    [["bash", "sh", "dash", "ksh"], ["shellcheck"]],
    [["wasm"], ["wasm_validate", "wasm_objdump"]],
@@ -224,8 +224,8 @@ tools_for_extensions = [
   command = "gcc -fsyntax-only -fdiagnostics-color=always"
   has_color = true
 
-[php7_syntax]
-  dependencies = ["php7.4-cli"]
+[php8_syntax]
+  dependencies = ["php8.0-cli"]
   url = "https://en.wikipedia.org/wiki/PHP"
   command = "php --syntax-check"