Update README.md

Author: regisbamba

README.md

@@ -67,12 +67,12 @@ collections.getAccountBalance().subscribe(
 You can also consume error events in case of the API request failed.
 ```java
 collections.createApiUser().subscribe(
-	new Consumer<AccountBalance>() {
-		@Override
-		public void accept(AccountBalance accountBalance) {                 // This function executes in case of success.
+    new Consumer<AccountBalance>() {
+        @Override
+        public void accept(AccountBalance accountBalance) {                 // This function executes in case of success.
             System.out.println(accountBalance.getAvailableBalance());       // 900
-		}
-	},
+        }
+    },
     new Consumer<Throwable>() {
         @Override
         public void accept(Throwable throwable) throws Exception {          // This function executes in case of errors.
@@ -93,13 +93,13 @@ collections.getAccountBalance().subscribe(accountBalance -> {     // This functi
 
 ```java
 collections.getAccountBalance().subscribe(
-	accountBalance -> {                                                 // This function executes in case of success.
-		System.out.println(accountBalance.getAvailableBalance());       // 900
-	},
+    accountBalance -> {                                                 // This function executes in case of success.
+        System.out.println(accountBalance.getAvailableBalance());       // 900
+    },
     throwable -> {                                                      // This function executes in case of error.
-         RequestException e = (RequestException) throwable;             // Cast the throwable to RequestException to get the HTTP code and message returned by the MoMo API.
-         System.out.println(e.getCode());                               // 401
-         System.out.println(e.getMessage());                            // Access denied due to invalid subscription key. Make sure to provide a valid key for an active subscription.
+        RequestException e = (RequestException) throwable;              // Cast the throwable to RequestException to get the HTTP code and message returned by the MoMo API.
+        System.out.println(e.getCode());                                // 401
+        System.out.println(e.getMessage());                             // Access denied due to invalid subscription key. Make sure to provide a valid key for an active subscription.
     }
 );
 ```
@@ -233,10 +233,10 @@ Documentation: https://momodeveloper.mtn.com/docs/services/collection/operations
 
 ```java
 collections.getRequestToPay(referenceId).subscribe(
-	requestToPay -> {
-		System.out.println(requestToPay.getFinancialTransactionId());	// 521734614
-		System.out.println(requestToPay.getStatus());                   // SUCCESSFUL
-	}
+    requestToPay -> {
+        System.out.println(requestToPay.getFinancialTransactionId());	// 521734614
+        System.out.println(requestToPay.getStatus());                   // SUCCESSFUL
+    }
 );
 ```
 
@@ -247,8 +247,8 @@ Documentation: https://momodeveloper.mtn.com/docs/services/collection/operations
 
 ```java
 collections.getAccountBalance().subscribe(accountBalance -> {
-	System.out.println(accountBalance.getAvailableBalance());   // 900
-	System.out.println(accountBalance.getCurrency());           // EUR
+    System.out.println(accountBalance.getAvailableBalance());   // 900
+    System.out.println(accountBalance.getCurrency());           // EUR
 });
 ```