Add fresh_after_build callback

Closes #80.

bin/fresh

@@ -69,13 +69,20 @@ To disable this error, add \`FRESH_NO_BIN_CHECK=true\` in your freshrc file."
   # remove the old build dir
   rm -rf "$FRESH_PATH/build.old"
 
+  fresh_after_build
+
   # success!
   if [ ! "$1" == "--quiet" ];
   then
     echo $'Your dot files are now \033[1;32mfresh\033[0m.'
   fi
 }
 
+# placeholder method that can be overridden in your freshrc
+fresh_after_build() {
+  true
+}
+
 _dsl_install_fresh() {
   _set_dsl_caller
   _parse_fresh_dsl_args "$@"

test/fresh_test.sh

@@ -1334,6 +1334,17 @@ it_allows_bin_fresh_error_to_be_disabled() {
   runFresh
 }
 
+it_runs_fresh_after_build() {
+  echo "fresh_after_build() { echo test after_build; }" >> $FRESH_RCFILE
+
+  runFresh
+
+  assertFileMatches $SANDBOX_PATH/out.log <<EOF
+test after_build
+$(echo $'Your dot files are now \033[1;32mfresh\033[0m.')
+EOF
+}
+
 assert_parse_fresh_dsl_args() {
   (
     set -e