CI: run workflows when .yml config files change (#832)

A few of the workflows were missing this

Author: tarcieri

.github/workflows/balloon-hash.yml

@@ -3,6 +3,7 @@ name: balloon-hash
 on:
   pull_request:
     paths:
+      - ".github/workflows/balloon-hash.yml"
       - "balloon-hash/**"
       - "Cargo.*"
   push:

.github/workflows/bcrypt-pbkdf.yml

@@ -3,6 +3,7 @@ name: bcrypt-pbkdf
 on:
   pull_request:
     paths:
+      - ".github/workflows/bcrypt-pbkdf.yml"
       - "bcrypt-pbkdf/**"
       - "Cargo.*"
   push:
@@ -39,7 +40,7 @@ jobs:
   minimal-versions:
     uses: RustCrypto/actions/.github/workflows/minimal-versions.yml@master
     with:
-        working-directory: ${{ github.workflow }}
+      working-directory: ${{ github.workflow }}
 
   test:
     runs-on: ubuntu-latest

.github/workflows/scrypt.yml

@@ -3,6 +3,7 @@ name: scrypt
 on:
   pull_request:
     paths:
+      - ".github/workflows/scrypt.yml"
       - "scrypt/**"
       - "Cargo.*"
   push:

.github/workflows/sha-crypt.yml

@@ -3,6 +3,7 @@ name: sha-crypt
 on:
   pull_request:
     paths:
+      - ".github/workflows/sha-crypt.yml"
       - "sha-crypt/**"
       - "Cargo.*"
   push: