Make the blake-related target equal to the created shared-object file

... so to allow make to detect that the target is already built.

.travis.yml

@@ -19,6 +19,6 @@ before_script:
   - LIBP="$(pwd)/src"
   - echo "The library path variable value is ${LIBP:?}"
 script:
-  - ( cd src && make blake2b; )
+  - ( cd src && make libblake2b.so; )
   - if test quick = "${JOB:?}"; then ( cd src && env ${LIBV:?}="${LIBP:?}" make test example; ); fi
   - if test demo30 = "${JOB:?}"; then ( cd src && env ${LIBV:?}="${LIBP:?}" make demo30; ); fi

src/Makefile

@@ -10,9 +10,9 @@ CFLAGS = -Wall -Wno-format -fomit-frame-pointer $(OPT)
 GCC = gcc -m64 -std=gnu11 $(CFLAGS)
 LIBS = -L. -lblake2b
 
-all : blake2b test example lean28stx8 mean28 lean30stx8 mean30 lean32stx8 mean32 verify28 verify30 verify32 demo30
+all : libblake2b.so test example lean28stx8 mean28 lean30stx8 mean30 lean32stx8 mean32 verify28 verify30 verify32 demo30
 
-blake2b:	blake2.h blake2-impl.h blake2b-ref.c
+libblake2b.so:	blake2.h blake2-impl.h blake2b-ref.c
 	$(GCC) -fPIC -shared -o libblake2b.so blake2b-ref.c
 	echo "add build dir to LD_LIBRARY_PATH (or DYLD_LIBRARY_PATH on Mac OSX) if library not found"