Fix compatibility warnings with Erlang/OTP 19. Bump app version to '1.3.2'

fix warnings

.gitignore

@@ -4,3 +4,5 @@ ebin
 TAGS
 .eunit
 erl_crash.dump
+rebar.lock
+_build

src/herd.app.src

@@ -1,7 +1,7 @@
 {application, herd,
  [
   {description, "Base library for erlang projects"},
-  {vsn, "1"},
+  {vsn, "1.3.2"},
   {modules, []},
   {registered, []},
   {applications, [kernel, stdlib]},

src/herd_datetime.erl

@@ -12,14 +12,12 @@
 
 -spec now() -> timestamp().
 now() ->
-    {Mega, Sec, _Micro} = erlang:now(),
-    Mega * 1000000 + Sec.
+    os:system_time(seconds).
 
 
 -spec now_micro() -> timestamp_micro().
 now_micro() ->
-    {Mega, Sec, Micro} = erlang:now(),
-    Mega * 1000000 + Sec + Micro * 1.0e-6.
+    os:system_time(micro_seconds) * 1.0e-6.
 
 
 -spec datetime_from_db(db_datetime()) -> calendar:datetime().

src/herd_rand.erl

@@ -8,8 +8,8 @@
 %% sets random seed for current process
 -spec init_crypto() -> ok.
 init_crypto() ->
-    <<A:32, B:32, C:32>> = crypto:rand_bytes(12),
-    random:seed({A,B,C}),
+    <<A:32, B:32, C:32>> = crypto:strong_rand_bytes(12),
+    rand:seed({A,B,C}),
     ok.
 
 
@@ -44,4 +44,4 @@ md5hex(Str) ->
 
 %% generates random md5 hash
 -spec hex() -> string().
-hex() -> md5hex(integer_to_list(erlang:phash2({now(), make_ref()}))).
+hex() -> md5hex(integer_to_list(erlang:phash2({erlang:unique_integer(), make_ref()}))).