Merge pull request #22 from wsanchez/mypy

Unsupported operand types for + ("Union[int, float]" and "int")

.travis.yml

@@ -24,8 +24,5 @@ matrix:
     - python: 3.5
       env: TOXENV=py35-trial-coverage,codecov_publish
 
-  allow_failures:
-    - env: TOXENV=lint-mypy
-
 script:
   - tox

src/sample_klein_app/application/math.py

@@ -51,7 +51,8 @@ def add(self, request: IRequest, a: str, b: str) -> KleinRenderable:
 
         @param b: A number to add to C{a}.
         """
-        return "{}".format(self.numberify(a) + self.numberify(b))
+        x = self.numberify(a) + self.numberify(b)  # type: ignore #see #21
+        return "{}".format(x)
 
     @router.route("/subtract/<a>/<b>")
     def subtract(self, request: IRequest, a: str, b: str) -> KleinRenderable:
@@ -67,7 +68,8 @@ def subtract(self, request: IRequest, a: str, b: str) -> KleinRenderable:
 
         @param b: A number to subtract from C{a}.
         """
-        return "{}".format(self.numberify(a) - self.numberify(b))
+        x = self.numberify(a) - self.numberify(b)  # type: ignore #see #21
+        return "{}".format(x)
 
     @router.route("/multiply/<a>/<b>")
     def multiply(self, request: IRequest, a: str, b: str) -> KleinRenderable:
@@ -82,7 +84,8 @@ def multiply(self, request: IRequest, a: str, b: str) -> KleinRenderable:
 
         @param b: A number to multiply with C{a}.
         """
-        return "{}".format(self.numberify(a) * self.numberify(b))
+        x = self.numberify(a) * self.numberify(b)  # type: ignore #see #21
+        return "{}".format(x)
 
     @router.route("/divide/<a>/<b>")
     def divide(self, request: IRequest, a: str, b: str) -> KleinRenderable:
@@ -98,7 +101,8 @@ def divide(self, request: IRequest, a: str, b: str) -> KleinRenderable:
 
         @param b: A number to divide C{a} by.
         """
-        return "{}".format(self.numberify(a) / self.numberify(b))
+        x = self.numberify(a) / self.numberify(b)  # type: ignore #see #21
+        return "{}".format(x)
 
     @router.handle_errors(ValueError)
     def valueError(self, request: IRequest, failure) -> KleinRenderable: