Fix pyyaml (#402)

* Revert "use pkg_resources to check for distributions (#395)"

This reverts commit 9b185f99d5.

* use sp-grep for django detection

* sp-grep

* fix setuptools script

bin/steps/collectstatic

@@ -20,7 +20,7 @@ MANAGE_FILE=${MANAGE_FILE:-fakepath}
 [ -f .heroku/collectstatic_disabled ] && DISABLE_COLLECTSTATIC=1
 
 # Ensure that Django is explicitly specified in requirements.txt
-pip-grep -s Django && DJANGO_INSTALLED=1
+sp-grep django && DJANGO_INSTALLED=1
 
 
 if [ ! "$DISABLE_COLLECTSTATIC" ] && [ -f "$MANAGE_FILE" ] && [ "$DJANGO_INSTALLED" ]; then

bin/steps/cryptography

@@ -18,7 +18,7 @@ PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"
 source $BIN_DIR/utils
 
 # If a package using cffi exists within requirements, use vendored libffi.
-if (pip-grep -s argon2-cffi bcrypt cffi cryptography PyNaCl pyOpenSSL PyOpenSSL misaka &> /dev/null) then
+if (pip-grep -s requirements.txt argon2-cffi bcrypt cffi cryptography django[argon2] Django[argon2] django[bcrypt] Django[bcrypt] PyNaCl pyOpenSSL PyOpenSSL requests[security] misaka &> /dev/null) then
 
   if [ ! -d ".heroku/vendor/lib/libffi-3.1" ]; then
     echo "-----> Noticed cffi. Bootstrapping libffi."

bin/steps/gdal

@@ -18,7 +18,7 @@ PKG_CONFIG_PATH="/app/.heroku/vendor/lib/pkgconfig:$PKG_CONFIG_PATH"
 source $BIN_DIR/utils
 
 # If GDAL exists within requirements, use vendored gdal.
-if (pip-grep -s GDAL pygdal &> /dev/null) then
+if (pip-grep -s requirements.txt GDAL gdal pygdal &> /dev/null) then
 
   if [ ! -f ".heroku/vendor/bin/gdalserver" ]; then
     echo "-----> Noticed GDAL. Bootstrapping gdal."

bin/steps/pylibmc

@@ -17,7 +17,7 @@ source $BIN_DIR/utils
 
 
 # If pylibmc exists within requirements, use vendored libmemcached.
-if (pip-grep -s pylibmc &> /dev/null) then
+if (pip-grep -s requirements.txt pylibmc &> /dev/null) then
 
   if [ ! -d ".heroku/vendor/lib/sasl2" ]; then
     echo "-----> Noticed pylibmc. Bootstrapping libmemcached."