Drop explicit PyPy support

PyPy will be supported inasmuch as it is compatible with the currently
supported Python version.

Author: oschwald

.travis.yml

@@ -8,8 +8,6 @@ matrix:
       env: RUN_LINTER=1
     - python: nightly
       dist: xenial
-    - python: pypy3
-      dist: trusty
   allow_failures:
     - python: nightly
 
@@ -32,8 +30,7 @@ before_install:
     fi
 
 script:
-  - if [[ $TRAVIS_PYTHON_VERSION != 'pypy' ]]; then export MM_FORCE_EXT_TESTS=1; fi
-  - CFLAGS="-Werror -Wall -Wextra" coverage run --source maxminddb setup.py test
+  - MM_FORCE_EXT_TESTS=1 CFLAGS="-Werror -Wall -Wextra" coverage run --source maxminddb setup.py test
   - if [[ $RUN_SNYK && $SNYK_TOKEN ]]; then snyk test --org=maxmind --file=requirements.txt; fi
   - if [[ $RUN_LINTER ]]; then mypy maxminddb tests; fi
   - if [[ $RUN_LINTER ]]; then pylint --rcfile .pylintrc maxminddb/*.py; fi

README.rst

@@ -94,8 +94,7 @@ Requirements
 ------------
 
 This code requires Python 3.7+. Older versions are not supported. The C
-extension requires CPython. The pure Python implementation has been tested with
-PyPy3.
+extension requires CPython.
 
 Versioning
 ----------