Use correct bash syntax for checking if a parameter exists and is true (#15)

* Make scripts executable

* Correct syntax of boolean checks

* Update example

Author: noahd1

src/examples/example.yml

@@ -5,7 +5,7 @@ description: >
 usage:
   version: 2.1
   orbs:
-    qlty: qltysh/qlty-orb@0.0.3
+    qlty: qltysh/qlty-orb@volatile
   jobs:
     run_tests_and_publish_coverage:
       docker:

src/scripts/install

@@ -25,19 +25,19 @@ add_param "--add-prefix" "$PARAM_ADD_PREFIX"
 add_param "--total-parts-count" "$PARAM_TOTAL_PARTS_COUNT"
 add_param "--format" "$PARAM_FORMAT"
 
-if $PARAM_VERBOSE; then
+if [ "$PARAM_VERBOSE" = "true" ]; then
   params+=("--verbose")
 fi
 
-if $PARAM_SKIP_MISSING_FILES; then
+if [ "$PARAM_SKIP_MISSING_FILES" = "true" ]; then
   params+=("--skip-missing-files")
 fi
 
-if $PARAM_DRY_RUN; then
+if [ "$PARAM_DRY_RUN" = "true" ]; then
   params+=("--dry-run")
 fi
 
-if $PARAM_INCOMPLETE; then
+if [ "$PARAM_INCOMPLETE" = "true" ]; then
   params+=("--incomplete")
 fi
 
@@ -46,7 +46,7 @@ if [[ -n $PARAM_UPLOAD_NAME ]]; then
   params+=("$PARAM_UPLOAD_NAME")
 fi
 
-if $PARAM_VALIDATE; then
+if [ "$PARAM_VALIDATE" = "true" ]; then
   params+=("--validate")
 
   if [[ -n $PARAM_VALIDATE_FILE_THRESHOLD ]]; then