Merge pull request #2299 from jchodera/update-version-number

Update version number to 7.4.0 to match nightly conda dev builds

CMakeLists.txt

@@ -157,7 +157,7 @@ ENDIF (NOT CMAKE_CXX_FLAGS_RELEASE)
 
 SET(OPENMM_LIBRARY_NAME OpenMM)
 SET(OPENMM_MAJOR_VERSION 7)
-SET(OPENMM_MINOR_VERSION 3)
+SET(OPENMM_MINOR_VERSION 4)
 SET(OPENMM_BUILD_VERSION 0)
 
 ADD_DEFINITIONS(-DOPENMM_LIBRARY_NAME=${OPENMM_LIBRARY_NAME}