Make things works on Python 3.5.2 again (#161)

* Make things works on Python 3.5.2 again

Also add 3.5 testing to Travis to prevent future regressions.

Closes #159.

* Skip running mypy on Python 3.5.

* Only install flake8-mypy on Python 3.6+

On 3.5 it gives errors about not being able to find a suitable Python
interpreter, which breaks the Travis tests.

.travis.yml

@@ -3,6 +3,7 @@ sudo: required
 
 
 python:
+  - '3.5'
   - '3.6'
 
 install:

Makefile

@@ -25,7 +25,9 @@ cov cover coverage: flake mypy checkrst
 	@echo "open file://`pwd`/htmlcov/index.html"
 
 mypy:
-	mypy aiomonitor --ignore-missing-imports --disallow-untyped-calls --disallow-incomplete-defs --strict
+	if ! python --version | grep -q 'Python 3\.5\.'; then \
+	    mypy aiomonitor --ignore-missing-imports --disallow-untyped-calls --disallow-incomplete-defs --strict; \
+	fi
 
 ci: flake mypy
 	py.test -s -v  --cov-report term --cov aiomonitor ./tests

aiomonitor/monitor.py

@@ -120,7 +120,10 @@ def __enter__(self) -> 'Monitor':
             self.start()
         return self
 
-    def __exit__(self, exc_type: Optional[Type[BaseException]],
+    # exc_type should be Optional[Type[BaseException]], but
+    # this runs into https://github.com/python/typing/issues/266
+    # on Python 3.5.
+    def __exit__(self, exc_type: Any,
                  exc_value: Optional[BaseException],
                  traceback: Optional[TracebackType]) -> None:
         self.close()
@@ -243,7 +246,7 @@ def map_args(self, cmd: Callable, args: Sequence[str]
         for param in params:
             if (param.annotation is param.empty or
                     not callable(param.annotation)):
-                type_: Callable[[Any], Any] = lambda x: x  # noqa
+                type_ = lambda x: x  # type: Callable[[Any], Any]  # noqa
             else:
                 type_ = param.annotation
             try:

requirements-dev.txt

@@ -4,7 +4,7 @@ aiohttp==3.4.4
 attrs==18.2.0
 docutils==0.14
 flake8-bugbear==18.8.0
-flake8-mypy==17.8.0
+flake8-mypy==17.8.0; python_version>='3.6'
 flake8-quotes==1.0.0
 flake8==3.5.0
 ipdb==0.11