Make the install script verify the checksum automatically (#104)

* Make the install script verify the checksum automatically

* Remove rm -rf in install script

install.sh

@@ -1,13 +1,12 @@
 #!/usr/bin/env bash
 set -eu
 
-VERSION="v0.3.0"
+VERSION="v0.4.0"
 DEST="/usr/local/bin"
 SHELL_LINE='eval "$(bud --shell-init --with-completion)"'
 
 YELLOW="\033[1;33m"
 BLUE="\033[1;34m"
-CYAN="\033[1;36m"
 WHITE="\033[1;37m"
 CODE="\033[44m\033[1;37m"
 LINK="\033[4m\033[1;34m"
@@ -55,22 +54,20 @@ instructions() {
 main() {
     banner
 
+    TMPDIR=$(mktemp -d)
+    cd "${TMPDIR}"
+
     header "Downloading binary from Github"
-    URL="https://github.com/devbuddy/devbuddy/releases/download/${VERSION}/bud-$(make_variant)"
-    TMPFILE=`mktemp`
-    curl -L -# --fail "${URL}" -o "${TMPFILE}"
+    BINARY="bud-$(make_variant)"
+    URL="https://github.com/devbuddy/devbuddy/releases/download/${VERSION}/${BINARY}"
+    curl -L -# --fail "${URL}" -o "${BINARY}"
+    curl -L -# --fail "${URL}.sha256" -o "${BINARY}.sha256"
 
-    header "Downloading SHA from Github"
-    expected_hash=$(curl -LsS --fail "${URL}.sha256")
-    downloaded_hash=$(shasum -a 256 "${TMPFILE}")
-    echo "Expected hash   : ${expected_hash}"
-    echo "Downloaded hash : ${downloaded_hash}"
-    read -p "Correct? [enter]"
+    header "Verify SHA256 checksum"
+    shasum -c "${BINARY}.sha256"
 
     header "Installing to ${DEST}"
-    sudo install "${TMPFILE}" "${DEST}/bud"
-
-    [[ -e "${TMPFILE}" ]] && unlink "${TMPFILE}"
+    sudo install "${BINARY}" "${DEST}/bud"
 
     instructions
 }