install-poetry.py: Use for 1.1.7 and up

See also:
- https://github.com/python-poetry/poetry/releases/tag/1.1.7
- asdf-community#10 (comment)

bin/install

@@ -31,7 +31,7 @@ install_poetry() {
     fail "asdf-poetry supports release installs only"
   fi
 
-  semver_ge "$ASDF_INSTALL_VERSION" 1.2.0 && vercomp="ge" || vercomp="lt"
+  semver_ge "$ASDF_INSTALL_VERSION" 1.1.7 && vercomp="ge" || vercomp="lt"
 
   if [ $vercomp == "ge" ]; then
     install_url="https://install.python-poetry.org"