We need the build requirments always. [skip travis]

appveyor.yml

@@ -138,7 +138,7 @@ install:
   # compiled extensions and are not provided as pre-built wheel packages,
   # pip will build them from source using the MSVC compiler matching the
   # target Python version and architecture
-  - if not "%GWHEEL_ONLY%"=="true" %CMD_IN_ENV% %PYEXE% -m pip install -U --upgrade-strategy=eager -r ci-requirements.txt
+  - "%CMD_IN_ENV% %PYEXE% -m pip install -U --upgrade-strategy=eager -r ci-requirements.txt"
 
   - ps: "if(Test-Path(\"${env:PYTHON}\\bin\")) {ls ${env:PYTHON}\\bin;}"
   - ps: "if(Test-Path(\"${env:PYTHON}\\Scripts\")) {ls ${env:PYTHON}\\Scripts;}"