Fix execution of scripts

For better script and argument support `run_script` is used instead of
`process::Command`.

Cargo.lock

@@ -331,6 +331,16 @@ dependencies = [
  "termcolor",
 ]
 
+[[package]]
+name = "fsio"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a50045aa8931ae01afbc5d72439e8f57f326becb8c70d07dfc816778eff3d167"
+dependencies = [
+ "rand",
+ "users",
+]
+
 [[package]]
 name = "funty"
 version = "1.1.0"
@@ -844,6 +854,15 @@ dependencies = [
  "unicode-xid 0.1.0",
 ]
 
+[[package]]
+name = "run_script"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1c022176d696304ff6655716c2c09e1b888c00ac66a7c53c037ae7c9511ce6c"
+dependencies = [
+ "fsio",
+]
+
 [[package]]
 name = "rust-argon2"
 version = "0.8.3"
@@ -1147,6 +1166,16 @@ dependencies = [
  "percent-encoding 1.0.1",
 ]
 
+[[package]]
+name = "users"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24cc0f6d6f267b73e5a2cadf007ba8f9bc39c6a6f9666f8cf25ea809a153b032"
+dependencies = [
+ "libc",
+ "log 0.4.14",
+]
+
 [[package]]
 name = "version_check"
 version = "0.1.5"
@@ -1185,6 +1214,7 @@ dependencies = [
  "nom",
  "regex",
  "rocket",
+ "run_script",
  "serde",
  "serde_json",
  "serde_yaml",