Revert "Add support for pre/post composer commands (#67)" (#69)

This reverts commit 0bc2391.

Author: OskarStark

README.md

@@ -48,19 +48,6 @@ _to install dev dependencies:_
         args: analyse src/
 ```
 
-_to execute some command before and/or after composer install:_
-```diff
-      uses: docker://oskarstark/phpstan-ga
-+     env:
-+       PRE_COMPOSER_COMMANDS:
-+         - composer config minimum-stability dev
-+         - composer config prefer-stable true
-+       POST_COMPOSER_COMMANDS:
-+         - composer outdated
-      with:
-        args: analyse src/
-```
-
 _to skip checking the platform requirements:_
 ```diff
       uses: docker://oskarstark/phpstan-ga

entrypoint.sh

@@ -18,21 +18,8 @@ if [ "$REQUIRE_DEV" = "true" ]; then
     NO_DEV=""
 fi
 
-if [ -z "$PRE_COMPOSER_COMMANDS" ]; then
-    for str in ${PRE_COMPOSER_COMMANDS[@]}; do
-        eval "$str"
-    done
-fi
-
 COMPOSER_COMMAND="composer install --no-progress $NO_DEV $IGNORE_PLATFORM_REQS"
 echo "::group::$COMPOSER_COMMAND"
-
-if [ -z "$POST_COMPOSER_COMMANDS" ]; then
-    for str in ${POST_COMPOSER_COMMANDS[@]}; do
-        eval "$str"
-    done
-fi
-
 $COMPOSER_COMMAND
 echo "::endgroup::"
 /composer/vendor/bin/phpstan $*