refactor appveyor

Author: isuruf

appveyor.yml

@@ -65,14 +65,15 @@ install:
 - if [%COMPILER%]==[MSVC15] call %CONDA_INSTALL_LOCN%\Scripts\activate.bat
 - if [%COMPILER%]==[MSVC15] conda config --add channels conda-forge
 - if [%COMPILER%]==[MSVC15] if [%BUILD_TYPE%]==[Debug] conda config --add channels symengine/label/debug
-- if [%COMPILER%]==[MSVC15] conda install --yes mpir=3.0.0 vc=14
+- if [%COMPILER%]==[MSVC15] set "CONDA_DEPS=mpir=3.0.0 vc=14"
+- if [%COMPILER%]==[MSVC15] if [%WITH_MPFR%]==[yes] set "CONDA_DEPS=%CONDA_DEPS% mpfr=3.1.5"
+- if [%COMPILER%]==[MSVC15] if [%WITH_MPC%]==[yes] set "CONDA_DEPS=%CONDA_DEPS% mpc=1.0.3"
+- if [%COMPILER%]==[MSVC15] if [%WITH_LLVM%]==[yes] set "CONDA_DEPS=%CONDA_DEPS% llvmdev=4.0"
+- if [%COMPILER%]==[MSVC15] conda install --yes %CONDA_DEPS%
 - if [%COMPILER%]==[MSVC15] echo %CONDA_PREFIX%
 - if [%COMPILER%]==[MSVC15] echo %PATH%
 - if [%COMPILER%]==[MSVC15] set "PATH=%PATH%;%CONDA_PREFIX%\\Library\\bin;%CONDA_PREFIX%"
 - if [%COMPILER%]==[MSVC15] echo %PATH%
-- if [%COMPILER%]==[MSVC15] if [%WITH_MPFR%]==[yes] conda install --yes mpfr=3.1.5
-- if [%COMPILER%]==[MSVC15] if [%WITH_MPC%]==[yes] conda install --yes mpc=1.0.3
-- if [%COMPILER%]==[MSVC15] if [%WITH_LLVM%]==[yes] conda install --yes llvmdev=4.0
 
 - if [%COMPILER%]==[MinGW] set "PATH=C:\MinGW\bin;%PATH%"
 - if [%COMPILER%]==[MinGW] mingw-get update