Implement decimal integer reading

scripts/build.sh

@@ -13,6 +13,9 @@ ar -crs build/lib.a build/memory_pool.o build/reader.o
 
 # Build tests
 clang $CFLAGS -Itests -c -o build/testing.o tests/testing.c
+clang $CFLAGS -Itests -c -o build/reader_tests.o tests/reader_tests.c
+clang $CFLAGS -o build/reader_tests \
+	  build/reader_tests.o build/lib.a build/testing.o
 
 # Build application
 clang $CFLAGS -c -o build/main.o app/main.c