release: update version to 0.1.5 (#52)

Co-authored-by: orangekame3 <[email protected]>

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "backend"
-version = "0.1.4"
+version = "0.1.5"
 description = "OQTOPUS Cloud is a project that provides the architecture of cloud quantum computers as an open-source software (OSS). By using it in conjunction with various OSS provided by [@oqtopus-team](https://github.com/oqtopus-team), you can build a cloud quantum computer system."
 authors = ["oqtopus-team <oqtopus-team[at]googlegroups.com>"]
 readme = "README.md"