refactor(cz/customize): make jinja2 a custom requirement. if not installed use string.Tempalte instead

Author: Lee-W

commitizen/cz/customize/customize.py

@@ -1,4 +1,7 @@
-from jinja2 import Template
+try:
+    from jinja2 import Template
+except ImportError:
+    from string import Template
 
 from commitizen import defaults
 from commitizen.cz.base import BaseCommitizen
@@ -27,7 +30,10 @@ def questions(self) -> list:
 
     def message(self, answers: dict) -> str:
         message_template = Template(self.custom_config.get("message_template"))
-        return message_template.render(**answers)
+        if getattr(Template, "substitute", None):
+            return message_template.substitute(**answers)
+        else:
+            return message_template.render(**answers)
 
     def example(self) -> str:
         return self.custom_config.get("example")

pyproject.toml

@@ -51,7 +51,7 @@ colorama = "^0.4.1"
 termcolor = "^1.1"
 packaging = "^19.0"
 tomlkit = "^0.5.3"
-jinja2 = "^2.10.3"
+jinja2 = {version = "^2.10.3", optional = true}
 
 [tool.poetry.dev-dependencies]
 ipython = "^7.2"