moved eta correction to own folder, add cmakelists

src/algorithms/EtaCorrection/CMakeLists.txt

+# Define module and return the generated name as ALGORITHM_NAME
+CORRYVRECKAN_ALGORITHM(ALGORITHM_NAME)
+
+# Add source files to library
+CORRYVRECKAN_ALGORITHM_SOURCES(${ALGORITHM_NAME}
+    EtaCorrection.cpp
+    # ADD SOURCE FILES HERE...
+)
+
+# Provide standard install target
+CORRYVRECKAN_ALGORITHM_INSTALL(${ALGORITHM_NAME})