Add basic LJ potential*

- Add PairPotential Abstract class
- Add Lennard-Jones potential that should work with both CUDA and C++
  code
- Add tests on HOST side for LJ potential

kernels/CMakeLists.txt

@@ -1,16 +1,14 @@
 project(${NAME}_cuda_lib CUDA CXX)
 
 set(HEADER_FILES
-    hello_world.h
+    pair_potentials.cuh
 )
 set(SOURCE_FILES
-    hello_world.cu
 )
 
 # The library contains header and source files.
-add_library(${NAME}_cuda_lib STATIC
+add_library(${NAME}_cuda_lib INTERFACE
     ${SOURCE_FILES}
     ${HEADER_FILES}
 )
 
-target_compile_options(${CMAKE_PROJECT_NAME}_cuda_lib PRIVATE -Wno-gnu-line-marker -Wno-pedantic)