module: declare Python 2.7 support as legacy

.github/dependabot.yml

@@ -1,36 +0,0 @@
----
-version: 2
-updates:
-- package-ecosystem: pip
-  directory: "/"
-  schedule:
-    interval: weekly
-    day: thursday
-    time: '14:00'
-    timezone: Europe/Berlin
-  pull-request-branch-name:
-    separator: "-"
-  open-pull-requests-limit: 99
-  commit-message:
-    prefix: "module:"
-  target-branch: three
-  versioning-strategy: lockfile-only
-  allow:
-  - dependency-type: direct
-  - dependency-type: indirect
-- package-ecosystem: pip
-  directory: "/"
-  schedule:
-    interval: weekly
-    day: thursday
-    time: '14:00'
-    timezone: Europe/Berlin
-  pull-request-branch-name:
-    separator: "-"
-  open-pull-requests-limit: 99
-  commit-message:
-    prefix: "module:"
-  versioning-strategy: lockfile-only
-  allow:
-  - dependency-type: direct
-  - dependency-type: indirect

.github/workflows/ci.yml

@@ -1,45 +0,0 @@
----
-name: ci
-
-on:
-  push:
-    branches: [master, three]
-  pull_request:
-    branches: [master, three]
-  workflow_dispatch:
-  schedule:
-  - cron: '41 4 * * 4'  # weekly on thursday morning
-
-jobs:
-  build:
-    runs-on: ubuntu-18.04
-    strategy:
-      fail-fast: false
-      matrix:
-        python-version:
-        - '2.7'
-        # Python 3.4 on GHA doesn't work due to fastdiff==0.2.0 failing with:
-        #   pkg_resources.DistributionNotFound: The 'setuptools_scm>=1.15.0' distribution was not found and is required by the application
-        #- '3.4'
-        - '3.5'
-        - '3.7'
-        - '3.9'
-    steps:
-    - uses: actions/checkout@v2
-    - run: python -m pip install --upgrade pip
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v2
-      with:
-        python-version: ${{ matrix.python-version }}
-    - name: Install Poetry
-      run: |
-        pip install poetry==1.0.10
-    - name: Install dependencies
-      run: |
-        poetry install
-    - name: Lint
-      run: |
-        make lint
-    - name: Test
-      run: |
-        make test

.travis.yml

@@ -1,13 +0,0 @@
----
-os: linux
-language: python
-python:
-- "3.4"
-
-install:
-- pip install poetry==1.0.10
-- poetry install
-
-script:
-- make lint
-- make test

Makefile

@@ -21,17 +21,6 @@ lint: ## Lint all source code
 test: ## Run all tests
 	poetry run pytest
 
-.PHONY: rebase-three-branch
-rebase-three-branch: ## Rebase the py3 branch with master contents
-	git stash
-	git checkout master
-	git pull
-	git checkout three
-	git rebase -i origin/master
-	git push --force-with-lease
-	git checkout master
-	git stash pop
-
 .PHONY: help
 help: ## Print this help text
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-15s\033[0m %s\n", $$1, $$2}'

README.md

@@ -1,6 +1,6 @@
 # python-bme280
 
-![ci](https://github.com/cmur2/python-bme280/workflows/ci/badge.svg?branch=master) [![Build Status](https://travis-ci.com/cmur2/python-bme280.svg?branch=master)](https://travis-ci.com/cmur2/python-bme280)
+**Note: This `legacy` branch is unmaintained and contains the Python 2.7 compatible code.**
 
 A Python library for accessing the [BME280 combined humidity and pressure](https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280_DS001-11.pdf) from Bosch via `python-smbus` using the I2C interface.