Added cleaning submodules to build.

Makefile

@@ -3,7 +3,6 @@
 SRC_DIR  := .
 OBJ_DIR  := obj
 LDFLAGS  := -lmbedcrypto
-CPPFLAGS :=
 CXXFLAGS := --std=c++14
 
 CXXFLAGS += -MMD -MP -Wall -Wfatal-errors -Wextra
@@ -29,6 +28,8 @@ $(OBJ_DIR):
 clean:
 	rm $(OBJ_DIR)/*
 	rm U2FDevice libuECC.a libcppb64.a
+	$(MAKE) -C micro-ecc clean
+	$(MAKE) -C cpp-base64 clean
 
 .PHONY: clean install
 

Scripts/cpp-base64-Makefile

@@ -16,4 +16,8 @@ $(OBJECTS): $(OBJ_DIR)/%.o: $(SRC_DIR)/%.cpp
 	@mkdir -p $(@D)
 	@$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c -o $@ $<
 
+clean:
+	rm obj/*
+	rm libcppb64.a
+
 -include $(OBJECTS:.o=.d)

Scripts/uECC-Makefile

@@ -22,4 +22,10 @@ $(OBJECTSI): $(OBJ_DIR)/%.o: $(SRC_DIR)/%.inc
 	@mkdir -p $(@D)
 	@$(CC) -x c $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
 
+clean:
+	rm obj/*
+	rm libuECC.a
+
+.PHONY: clean
+
 -include $(OBJECTS:.o=.d)