cmake: Use GNUInstallDirs instead of hard-coded paths

This ensures that it can be built on platforms where libdir is not
/usr/lib e.g. ppc64

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Closes #749
diff --git a/lang/c/CMakeLists.txt b/lang/c/CMakeLists.txt
index b75418c..6c8d7aa 100644
--- a/lang/c/CMakeLists.txt
+++ b/lang/c/CMakeLists.txt
@@ -16,8 +16,8 @@
 # specific language governing permissions and limitations
 # under the License.
 #
-cmake_minimum_required(VERSION 2.4)
-project(AvroC C)
+cmake_minimum_required(VERSION 3.1)
+project(AvroC)
 enable_testing()
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_SOURCE_DIR})
diff --git a/lang/c/src/CMakeLists.txt b/lang/c/src/CMakeLists.txt
index 6f56597..c1761c8 100644
--- a/lang/c/src/CMakeLists.txt
+++ b/lang/c/src/CMakeLists.txt
@@ -106,17 +106,19 @@
         DESTINATION include
         FILES_MATCHING PATTERN "*.h")
 
+include(GNUInstallDirs)
+
 if (WIN32)
 install(TARGETS avro-static
-        RUNTIME DESTINATION bin
-        LIBRARY DESTINATION lib
-        ARCHIVE DESTINATION lib
+	RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
        )
 else(WIN32)
 install(TARGETS avro-static avro-shared
-        RUNTIME DESTINATION bin
-        LIBRARY DESTINATION lib
-        ARCHIVE DESTINATION lib
+	RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+	LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
        )
 endif(WIN32)
 
@@ -126,7 +128,7 @@
 set(VERSION ${AVRO_VERSION})
 configure_file(avro-c.pc.in avro-c.pc)
 install(FILES ${CMAKE_CURRENT_BINARY_DIR}/avro-c.pc
-        DESTINATION lib/pkgconfig)
+        DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
 
 add_executable(avrocat avrocat.c)
 target_link_libraries(avrocat avro-static)