Remove reference to now removed SpectrumChartD3StandAlone.css

This fix is thanks to @furutaka in issue #33.

Author: wcjohns

target/electron/CMakeLists.txt

@@ -67,7 +67,6 @@ install( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../../InterSpec_resources DESTINA
 install( FILES ${CMAKE_CURRENT_BINARY_DIR}/LibInterSpec/InterSpec_resources/d3.v3.min.js
         ${CMAKE_CURRENT_BINARY_DIR}/LibInterSpec/InterSpec_resources/SpectrumChartD3.css
         ${CMAKE_CURRENT_BINARY_DIR}/LibInterSpec/InterSpec_resources/SpectrumChartD3.js
-        ${CMAKE_CURRENT_BINARY_DIR}/LibInterSpec/InterSpec_resources/SpectrumChartD3StandAlone.css
          DESTINATION ${PROJECT_BINARY_DIR}/app/InterSpec_resources/ )
 install( DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../../example_spectra DESTINATION ${PROJECT_BINARY_DIR}/app/ )
 install( FILES ${CMAKE_CURRENT_SOURCE_DIR}/app/loading.html