Update composer.json (#175)

* Update composer.json

* Update package requirements

* Apply fixes from StyleCI (#176)

* Update php version requirement

Author: musonza

.travis.yml

@@ -1,7 +1,6 @@
 language: php
 
 php:
-  - 7.1
   - 7.2
 
 env:

composer.json

@@ -9,13 +9,13 @@
         "conversation"
     ],
     "require": {
-        "php": ">=7.0",
-        "laravel/framework": "~5.4.0|~5.5.0|~5.6.0|~5.7.0|~5.8.0|~6.0.0"
+        "php": "^7.2",
+        "laravel/framework": "~5.8.0|^6.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.7|6.2|^7.0",
-        "orchestra/testbench": "~3.3.0|~3.4.2|^3.5.0|~3.7.0",
-        "orchestra/database": "~3.3.0|~3.4.2|^3.5.0|~3.7.0",
+        "phpunit/phpunit": "^7.0|^8.0",
+        "orchestra/testbench": "^3.8|^4.0",
+        "orchestra/database": "^3.8|^4.0",
         "mockery/mockery": "^1.0.0"
     },
     "license": "MIT",