[deps] Update version of Base

caisar.opam

@@ -19,7 +19,7 @@ depends: [
   "piqilib" {>= "0.6.14"}
   "zarith" {>= "1.7"}
   "ocplib-endian" {>= "1.0"}
-  "base" {>= "v0.14.0"}
+  "base" {>= "v0.15.1"}
   "stdio" {>= "v0.14.0"}
   "cmdliner" {>= "1.1.1"}
   "fmt" {>= "0.8.9"}

dune-project

@@ -27,7 +27,7 @@
    (piqilib (>= 0.6.14))
    (zarith (>= 1.7))
    (ocplib-endian (>= 1.0))
-   (base (>= v0.14.0))
+   (base (>= v0.15.1))
    (stdio (>= v0.14.0))
    (cmdliner (>= 1.1.1))
    (fmt (>= 0.8.9))